View source for Nickel double salts

{{short description|Class of chemical compounds}}
Nickel is one of the metals that can form [[Tutton's salts]]. The singly charged ion can be any of the full range of potassium, rubidium, cesium, ammonium (<chem>NH4</chem>), or thallium.<ref name="Wang2008">{{cite journal |last=Wang |first=Xia  |author2=Xinxin Zhuang  |author3=Genbo Su  |author4=Youping He |year=2008 
|title=A new ultraviolet filter: <math chem>\ce{Rb2Ni(SO4)2.6H2O}</math> (RNSH) single crystal 
|journal=Optical Materials |volume=31 |issue=2 |pages=233–236 |issn=0925-3467 |doi=10.1016/j.optmat.2008.03.020 
|url=http://ir.fjirsm.ac.cn/bitstream/350002/5857/1/Wang-2008-A%20new%20ultraviolet%20fi.pdf|bibcode=2008OptMa..31..233W  }}</ref> As a mineral the ammonium nickel salt, (NH<sub>4</sub>)<sub>2</sub>Ni(SO<sub>4</sub>)<sub>2</sub>{{hydrate|6}}, can be called nickelboussingaultite.<ref>{{cite web 
|title=Nickelboussingaultite: Nickelboussingaultite mineral information and data. 
|url=http://www.mindat.org/min-2896.html |website=www.mindat.org |access-date=3 May 2016}}</ref> With sodium, the double sulfate is nickelblödite Na<sub>2</sub>Ni(SO<sub>4</sub>)<sub>2</sub>{{hydrate|4}} from the [[blödite family]]. Nickel can be substituted by other divalent metals of similar sized to make mixtures that crystallise in the same form.<ref>{{cite web 
|title=Nickelblödite: Nickelblödite mineral information and data. 
|url=http://www.mindat.org/min-2890.html |website=www.mindat.org |access-date=4 May 2016}}</ref>

Nickel forms double salts with Tutton's salt structure with [[tetrafluoroberyllate]] with the range of cations of ammonia,<ref>{{cite journal |last1=Montgomery |first1=H. 
|title=Diammonium nickel bis(tetrafluoroberyllate)hexahydrate 
|journal=Acta Crystallographica Section B  
|date=15 September 1980 |volume=36 |issue=9 |pages=2121–2123 |doi=10.1107/S0567740880008060|doi-access=free |bibcode=1980AcCrB..36.2121M 
}}</ref> potassium, rubidium, cesium,<ref>{{cite journal |last1=Rây |first1=Nirmalendunath 
|title=Fluoberyllate und ihre Analogie mit Sulfaten. IV. Doppelsalze mit Rubidium- und Cäsiumfluoberyllaten 
|journal=Zeitschrift für anorganische und allgemeine Chemie 
|date=18 April 1936 |volume=227 |issue=1 |pages=32–36 |language=de |doi=10.1002/zaac.19362270105}}</ref> and thallium.<ref>{{cite journal |last1=Bose |first1=A. |last2=Mitra |first2=S. C. |last3=Datta |first3=S. K. 
|title=The Behaviour of the Paramagnetic Ions in the Single Crystals of Some Similarly Constituted Salts of the Iron Group of Elements. II. Hydrated NiFormula Salts 
|journal=Proceedings of the Royal Society A  
|date=11 November 1958 |volume=248 |issue=1253 |pages=153–168 |doi=10.1098/rspa.1958.0236|bibcode=1958RSPSA.248..153B |s2cid=98423115 }}</ref>

Anhydrous salts of the formula M<sub>2</sub>Ni<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>, which can be termed metal nickel trisulfates, belong to the family of [[langbeinites]]. The known salts include (NH<sub>4</sub>)<sub>2</sub>Ni<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>, K<sub>2</sub>Ni<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub> and Rb<sub>2</sub>Ni<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>, and those of Tl and Cs are predicted to exist.

Some minerals are double salts, for example [[Nickelzippeite]] Ni<sub>2</sub>(UO<sub>2</sub>)<sub>6</sub>(SO<sub>4</sub>)<sub>3</sub>(OH)<sub>10</sub> · 16H<sub>2</sub>O which is isomorphic to [[cobaltzippeite]], [[magnesiozippeite]] and [[zinczippeite]], part of the [[zippeite]] group.<ref>{{cite web 
|title=Nickelzippeite: Nickelzippeite mineral information and data. 
|url=http://www.mindat.org/min-2898.html |website=www.mindat.org |access-date=10 May 2016}}</ref>

Double hydrides of nickel exist, such as Mg<sub>2</sub>NiH<sub>4</sub>.<ref>{{cite journal |last1=Reilly |first1=James J. |last2=Wiswall |first2=Richard H. 
|title=Reaction of hydrogen with alloys of magnesium and nickel and the formation of <math chem>\ce{Mg2NiH4}</math>
|journal=Inorganic Chemistry 
|date=November 1968 |volume=7 |issue=11 |pages=2254–2256 |doi=10.1021/ic50069a016}}</ref>

{|class="wikitable"
!formula
!name
!mol
!struct
!colspan=3|cell Å
!°
!V
!Z
!density
!colour
!refs
|-
!
!
!wt
!
!a
!b
!c
!β
!Å<sup>3</sup>
!
!g/cm<sup>3</sup>
!
!
|-
|Li<sub>2</sub>[NiF(PO<sub>4</sub>)]
|Lithium nickel fluorophosphate
|186.56
|orthorhombic
|10.473
|6.289
|10.846
|
|714.3
|8
|3.469
|
|<ref>{{cite journal |last1=Dutreilh |first1=M. |last2=Chevalier |first2=C. |last3=El-Ghozzi |first3=M. |last4=Avignant |first4=D. |last5=Montel |first5=J.M. 
|title=Synthesis and Crystal Structure of a New Lithium Nickel Fluorophosphate <math chem>\ce{Li2[NiF(PO4)]}</math> with an Ordered Mixed Anionic Framework 
|journal=Journal of Solid State Chemistry 
|date=January 1999 |volume=142 |issue=1 |pages=1–5 |doi=10.1006/jssc.1998.7908 
|bibcode=1999JSSCh.142....1D }}</ref>
|-
|Na<sub>2</sub>[NiF(PO<sub>4</sub>)]
|sodium nickel fluorophosphate
|218.645
|''Pbcn''
|
|
|
|90
|823.4
|
|
|
|<ref>{{cite journal |last1=Ellis |first1=Brian L. |last2=Makahnouk |first2=W. R. Michael |last3=Rowan-Weetaluktuk |first3=W. N. |last4=Ryan |first4=D. H. |last5=Nazar |first5=Linda F. 
|title=Crystal Structure and Electrochemical Properties of <math chem>\ce{A2 MPO4 F}</math> Fluorophosphates (A=Na, Li; M=Fe, Mn, Co, Ni) 
|journal=Chemistry of Materials 
|date=9 February 2010 |volume=22 |issue=3 |pages=1059–1070 |doi=10.1021/cm902023h}}</ref>
|-
|Na<sub>2</sub>Ni(SO<sub>4</sub>)<sub>2</sub>{{hydrate|4}}
|nickelblödite
|368.867
|monoclinic
|11.045
|8.193
|5.535
|100.50
|
|
|2.487
|green
|<ref>{{cite journal |last1=Nickel |first1=E. H. |last2=Bridge |first2=P. J. 
|title=Nickelblödite <math chem>\ce{Na2Ni(SO4)2.4H2O}</math>, a new mineral from Western Australia 
|journal=Mineralogical Magazine 
|date=March 1977 |volume=41 |issue=317 |pages=37–41 
|url=http://rruff.info/doclib/mm/vol41/MM41_37.pdf |access-date=10 July 2016|bibcode=1977MinM...41...37N |doi=10.1180/minmag.1977.041.317.06 |s2cid=128668262 }}</ref>
|-
|K<sub>2</sub>Ni<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>
|potassium nickel trisulfate
|483.77
|orthorhombic
|9.8436
|9.8436
|9.8436
|90
|
|
|3.369
|
|<ref name="Swanson6-46">{{cite web 
|url=http://digicoll.manoa.hawaii.edu/techreports/PDF/NBS25-6.pdf 
|title=Standard X-ray Diffraction Powder Patterns |last=Swanson |first=H. E. |author2=H. F. McMurdie  |author3=M. C. Morris  |author4=E. H. Evans  
|date=September 1970 |work=National Bureau of Standards Monograph 25 Section 6 |publisher=National Bureau of Standards |page=46 |access-date=5 July 2013}}</ref>
|-
|Rb<sub>2</sub>Ni<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>
|rubidium nickel trisulfate
|576.51
|
|9.9217
|9.9217
|9.9217
|90
|
|
|3.921
|
|<ref name="Swanson8-72">{{cite web 
|url=http://digicoll.manoa.hawaii.edu/techreports/PDF/NBS25-8.pdf 
|title=Standard X-ray Diffraction Powder Patterns |last=Swanson |first=H. E. |author2=H. F. McMurdie  |author3=M. C. Morris  |author4=E. H. Evans  
|date=September 1970 |work=National Bureau of Standards Monograph 25 Section 8 |publisher=National Bureau of Standards |page=72 |access-date=5 July 2013}}</ref>
|-
|(NH<sub>4</sub>)<sub>2</sub>Ni<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>
|ammonium nickel trisulfate
|441.65
|orthorhombic
|9.904
|9.904
|9.904
|90
|
|
|3.02
|
|<ref name=NIMS>[http://crystdb.nims.go.jp AtomWork materials database at NIMS]</ref>
|-
|(NH<sub>4</sub>)<sub>4</sub>Ni<sub>3</sub>(SO<sub>4</sub>)<sub>5</sub>
|ammonium nickel pentasulfate
|728.56
|
|
|
|
|
|
|
|
|yellow
|<ref>{{cite journal |last1=Lepierre |first1=Ch. |last2=Lachaud |first2=M. 
|title=Chimie Minerale - Recherche sur le nickel et le cobalt 
|journal=Comptes rendus hebdomadaires des séances de l'Académie des sciences 
|date=1 July 1892 |volume=115 |page=115 
|url=http://gallica.bnf.fr/ark:/12148/bpt6k3071t/f115.item.zoom |access-date=11 July 2016}}</ref>
|-
|NiLa(SeO<sub>3</sub>)<sub>2</sub>Cl
|nickel lanthanum diselenite chloride
|486.977
|hexagonal
|8.666
|
|18.662
|
|1194.2
|6
|
|(153K)
|<ref>{{cite thesis|last1=Hamida|first1=Makram Ben
|title=Oxo-Selenate(IV) und Oxo-Arsenate(III) der SeltenErd-Metalle und ihre Derivate
|date=July 2007|location=Carl von Ossietzky Universität Oldenburg|page=147}}</ref>
|-
|NiNd<sub>10</sub>(SeO<sub>3</sub>)<sub>12</sub>Cl<sub>8</sub>
|nickel Neodymium diselenite chloride
|
|monoclinic
|15.8175
|1578,68
|19.276
|114.202
|7407
|4
|
|(153K)
|<ref>{{cite thesis|last1=Hamida|first1=Makram Ben
|title=Oxo-Selenate(IV) und Oxo-Arsenate(III) der SeltenErd-Metalle und ihre Derivate
|date=July 2007|location=Carl von Ossietzky Universität Oldenburg|page=149}}</ref>
|-
|Ni<sub>6</sub>Fe<sup>3+</sup><sub>2</sub>(SO<sub>4</sub>)(OH)<sub>16</sub>{{hydrate|4}}
|honessite
| 904.08
|trigonal
|3.083 
|
|26.71
|
|219.86
|0.25
|1.71
|green
|<ref>{{cite web |last1=Barthelmy |first1=Dave 
|title=Honessite Mineral Data 
|url=http://webmineral.com/data/Honessite.shtml#.V4JFJTXm7uc |website=webmineral.com |access-date=10 July 2016}}</ref>
|-
|NiTi(SO<sub>4</sub>)<sub>3</sub>
|nickel titanium sulfate
|
|monoclinic
| 8.254
| 8.54
|14.1444 
|124.967
|817
|4
|3.21
|
|<ref>{{cite web 
|title=<math chem>\ce{NiTi(SO4)3 (TiNi[SO4]3)}</math> Crystal Structure 
|url=https://materials.springer.com/isp/crystallographic/docs/sd_0307171 |publisher=Springer}}</ref>
|-
|Na<sub>2</sub>Ni(SeO<sub>4</sub>)<sub>2</sub>{{hydrate|2}}
|sodium nickel selenate dihydrate
|
|triclinic
|5.507
|5.905
|7.172
|α = 108.56 °, β = 99.07 °, γ = 106.35 °
|204.2
|1
|
|
|<ref>{{cite web 
|title=AtomWork 
|url=http://crystdb.nims.go.jp/crystdb/search-details?substance_id=36175&tabDetail=pageS&need_more_value=&pageD=0&reference_id=4294985181&pageA=1&pageSubP=1&errorCode=0&pageSubD=1&pageSubA=1&isVisiblePeriodicTable=true&tab=pageA&tabSub=pageA&isNeedMoreValueError=false&search-type=search-materials&condition_type=chemical_system&history=true&pageS=1&pageP=0&pageSubS=1&condition_value=O+Se+Ni+Na+H&need_more_type=prototype_number&material_id=4295516555&page=1&isConditionValueError=false}}</ref>
|-
|K<sub>2</sub>Ni(SeO<sub>4</sub>)<sub>2</sub>{{hydrate|2}}
|potassium nickel selenate dihydrate
|
|
|
|
|
|
|
|
|
|
|<ref>{{cite journal |last1=Ebert |first1=M. |last2=Vojtíšek |first2=P. 
|title=The Hydrates of Double Selenates 
|journal=Chemical Papers 
|date=1993 |volume=47 |issue=5 |pages=292–296 
|url=http://www.chempap.org/?id=7&paper=3746}}{{open access}}</ref>
|-
|K<sub>2</sub>Ni(SeO<sub>4</sub>)<sub>2</sub>{{hydrate|6}}
|potassium nickel selenate Tuttons salt
|527.52
|monoclinic
|a
|b
|c
|104.45
|
|4
|2.559
|bright green
|<ref name="tutsel">{{cite journal |last1=Tutton |first1=A. E. H. 
|title=Monoclinic Double Selenates of the Nickel Group 
|journal=Philosophical Transactions of the Royal Society of London A  
|date=1 January 1918 |volume=217 |issue=549–560 
|pages=199–235 |jstor=91121 |doi=10.1098/rsta.1918.0006|bibcode=1918RSPTA.217..199T |doi-access=free }}</ref>
|-
|Rb<sub>2</sub>Ni(SeO<sub>4</sub>)<sub>2</sub>{{hydrate|6}}
|rubidium nickel selenate Tuttons salt
|619.62
|monoclinic
|a
|b
|c
|105.20
|
|4
|2.856
|bright green
|<ref name="tutsel"/>
|-
|Cs<sub>2</sub>Ni(SeO<sub>4</sub>)<sub>2</sub>{{hydrate|6}}
|caesium nickel selenate Tuttons salt
|713.62
|monoclinic
|9.426
|12.961
|6.473
|106.17
|759.5
|2
|3.114
|bright emerald green
|<ref name="tutsel"/><ref>{{cite journal |last1=Euler |first1=Η. |last2=Barbier |first2=Β. |last3=Meents |first3=A. |last4=Kirfel |first4=A. 
|title=Crystal structure of Tutton′s salts, <math chem>\ce{Cs2[M^{II}(H2O)6](SeO4)2}</math>, M=Mg, Mn, Co, Ni, Zn 
|journal=Zeitschrift für Kristallographie - New Crystal Structures 
|date=January 2003 |volume=218 |issue=JG |doi=10.1524/ncrs.2003.218.jg.437|doi-access=free }} open access</ref>
|-
|(NH<sub>4</sub>)<sub>2</sub>Ni(SeO<sub>4</sub>)<sub>2</sub>{{hydrate|6}}
|ammonium nickel selenate Tuttons salt
|485.68
|monoclinic
|a
|b
|c
|106.29
|
|4
|2.243
|bright green
|<ref name="tutsel"/>
|-
|Tl<sub>2</sub>Ni(SeO<sub>4</sub>)<sub>2</sub>{{hydrate|6}}
|thallium nickel selenate Tuttons salt
|
|monoclinic
|a
|b
|c
|105.60
|
|4
|3.993
|bright green
|<ref>{{cite journal |last1=Tutton |first1=A. E. H. 
|title=The Hexahydrated Double Selenates Containing Thallium. Completion of the Thallium Salts and of the Whole Monoclinic Series 
|journal=Proceedings of the Royal Society of London A  
|date=1 January 1928 |volume=118 |issue=780 |pages=393–426 |jstor=94913|bibcode=1928RSPSA.118..393T |doi=10.1098/rspa.1928.0060 |doi-access=free }}</ref>
|-
|K<sub>2</sub>NiP<sub>2</sub>O<sub>7</sub>
|
|310.85
|monoclinic P2<sub>1</sub>
|9.230
|17.540
|8.32
|91.44
|1346.3
|8
|3.067
|
|<ref name="ElMaadi"/>
|-
|K<sub>6</sub>Sr<sub>2</sub>Ni<sub>5</sub>(P<sub>2</sub>O<sub>7</sub>)<sub>5</sub>
|
|786.55
|monoclinic P2<sub>1</sub>/c
|11.038
|9.53
|7.438
|100.13
|1578
|2
|3.309
|yellow
|<ref name="ElMaadi">{{cite journal |last1=ElMaadi |first1=A. |last2=Boukhari |first2=A. |last3=Holt |first3=E. M. 
|title=Crystal structures of the new diphosphates, <math chem>\ce{K2NiP2O7}</math> and <math chem>\ce{K6Sr2Ni5(P2O7)5}</math>
|journal=Journal of Chemical Crystallography 
|date=September 1995 |volume=25 |issue=9 |pages=531–536 |doi=10.1007/BF01667020|s2cid=95809818 }}</ref>
|-
|NaNi<sub>2</sub>(SO<sub>4</sub>)<sub>2</sub>[(H<sub>2</sub>O)(OH)]
|
|
|monoclinic ''C''2/''m'' Natrochalcite-type
|8.605
|6.185
|7.336
|114.78
|354.5
|2
|
|
|<ref>{{cite journal |last1=Krickl |first1=Robert |last2=Wildner |first2=Manfred 
|title=Crystal chemistry of synthetic Co- and Ni-analogues of natrochalcite – the shortest known hydrogen bonds among mineral-type compounds Part I: Single-crystal X-ray structures 
|journal=European Journal of Mineralogy 
|date=1 November 2007 |volume=19 |issue=6 |pages=805–816 |doi=10.1127/0935-1221/2007/0019-1770|bibcode=2007EJMin..19..805K }}</ref>
|-
|BaNi<sub>2</sub>(PO<sub>4</sub>)<sub>2</sub>
|barium nickel phosphate
|
|Trigonal R-3
|4.8112
|4.8112
|23.302
|
|467.1
|3
|
|green
|<ref name="elbali">{{cite journal |last1=El-Bali |first1=B. |last2=Bolte |first2=M. |last3=Boukhari |first3=A. |last4=Aride |first4=J. |last5=Taibe |first5=M. 
|title=<math chem>\ce{BaNi2 (PO4 )2}</math>
|journal=Acta Crystallographica Section C  
|date=15 May 1999 |volume=55 |issue=5 |pages=701–702 |doi=10.1107/S0108270199000499}}</ref>
|-
|BaNi<sub>2</sub>(AsO<sub>4</sub>)<sub>2</sub>
|barium nickel arsenate
|
|Trigonal R-3
|4.945
|4.945
|23.61
|
|532.59
|3
|5.31
|
|<ref name="elbali"/>
|-
|BaNi<sub>2</sub>(VO<sub>4</sub>)<sub>2</sub>
|barium nickel vanadate
|
|Trigonal R-3
|5.0375
|5.0375
|22.33
|
|
|3
|
|
|<ref>{{cite journal |last1=Rogado |first1=N. |last2=Huang |first2=Q. |last3=Lynn |first3=J. W. |last4=Ramirez |first4=A. P. |last5=Huse |first5=D. |last6=Cava |first6=R. J. 
|title=A two-dimensional honeycomb antiferromagnet 
|journal=Physical Review B 
|date=4 April 2002 |volume=65 |issue=14 |page=144443 |doi=10.1103/PhysRevB.65.144443|bibcode=2002PhRvB..65n4443R }}</ref>
|-
|Na<sub>4</sub>Ni<sub>7</sub>(AsO<sub>4</sub>)<sub>6</sub>
|tetrasodium heptanickel hexaarsenate
|1336.3
|monoclinic ''C''2/''m''
|14.538
|14.505
|10.6120
|118.299
|1970.3
|4
|
|brown
|<ref>{{cite journal |last1=David |first1=Rénald 
|title=Synthesis and crystal structure of <math chem>\ce{Na4Ni7(AsO4)6}</math>
|journal=Acta Crystallographica Section E  
|date=5 April 2016 |volume=72 |issue=5 |pages=632–634 |doi=10.1107/S2056989016005417 
|pmid=27308006 
|pmc=4908513 
|url=http://journals.iucr.org/e/issues/2016/05/00/vn2109/vn2109.pdf |access-date=16 July 2016|doi-access=free }}</ref>
|-
|K<sub>2</sub>Ni(CO<sub>3</sub>)<sub>2</sub>{{hydrate}}
|potassium nickel carbonate<br/>Potassium tetraaquadicarbonatonickelate
|
|monoclinic Baylissite-type
|6.755
|6.156
|12.2406
|113.265
|467.6
|2
|2.34 
|
|<ref>{{cite journal |last1=Zheng |first1=Y. Q. |last2=Adam |first2=A. 
|title=Potassium trans-tetraaquadicarbonatonickelate(II), <math chem>\ce{K2[Ni(CO3)2(H2O)4]}</math>
|journal=Acta Crystallographica Section C  
|date=15 September 1994 |volume=50 |issue=9 |pages=1422–1424 |doi=10.1107/S0108270193012855}}</ref>
|-
|Rb<sub>2</sub>Ni(CO<sub>3</sub>)<sub>2</sub>{{hydrate}}
|Rubidium nickel carbonate
|
|monoclinic Baylissite-type
|6.971
|6.348
|12.2807
|114.289
|495.34
|2
|2.83
|
|<ref>{{cite journal |last1=Zheng |first1=Y. Q. |last2=Adam |first2=A. 
|title=Crystal structure of dirubidium trans-tetraaquabis(carbonato)-cobaltate(II), <math chem>\ce{Rb2[Co(CO3)2(H2O)4]}</math> and dirubidium trans-tetraaquabis(carbonato)-nickelate(II), <math chem>\ce{Rb2[Ni(CO3)2(H2O)4]}</math>
|journal=Zeitschrift für Kristallographie - Crystalline Materials 
|date=1 January 1995 |volume=210 |issue=6 |page=447 |doi=10.1524/zkri.1995.210.6.447|bibcode=1995ZK....210..447Z }}</ref>
|-
|NiTh(NO<sub>3</sub>)<sub>6</sub>{{hydrate|8}}
|nickel thorium nitrate
|
|Monoclinic ''P''2<sub>1</sub>/''c''
|9.089
|8.728
|13.565
|96.65
|1068.8(2)
|
|
|
|<ref name="Cherno"/>
|-
|K[NiGa<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub>(H<sub>2</sub>O)<sub>2</sub>]
|Potassium nickel(II) gallium phosphate hydrate
|558.17
|Monoclinic ''C''2/''c''
|13.209
|10.173
|8.813
|107.68
|1128.4
|Z = 4
|
|
|<ref>{{cite journal |last1=Chippindale |first1=AM |last2=Sharma |first2=AV |last3=Hibble |first3=SJ 
|title=Potassium nickel(II) gallium phosphate hydrate, <math chem>\ce{K[NiGa2(PO4)3(H2O)2]}</math>. 
|journal=Acta Crystallographica Section E  
|date=30 April 2009 |volume=65 |issue=Pt 5 |pages=i38–i39 |pmid=21583729 |doi=10.1107/s1600536809015438 |pmc=2977543}}</ref>
|-
|KNi<sub>3</sub>(PO<sub>4</sub>)P<sub>2</sub>O<sub>7</sub>
|Potassium trinickel(II) orthophosphate diphosphate
|484.14
|Monoclinic
|9.8591
|9.3953
|9.9778
|118.965
|808.63
|4
|
|
|<ref>{{cite journal |last1=Moutataouia |first1=Meryem |last2=Lamire |first2=Mohammed |last3=Saadi |first3=Mohamed |last4=El Ammari |first4=Lahcen 
|title=Potassium trinickel(II) orthophosphate diphosphate, <math chem>\ce{KNi3(PO4 )P7O7 }</math>
|journal=Acta Crystallographica Section E  
|date=24 December 2013 |volume=70 |issue=1 |pages=i5 |doi=10.1107/S1600536813034089|pmid=24526940 |pmc=3914035 }}</ref>
|-
|KNiPO<sub>4</sub>
|potassium nickel phosphate
|
|
|
|
|
|
|
|
|
|
|<ref>{{cite journal |last1=Galoisy |first1=L |last2=Calas |first2=G 
|title=XANES and crystal field spectroscopy of five-coordinated Nickel(II) in potassium-nickel phosphate 
|journal=Materials Research Bulletin 
|date=March 1993 |volume=28 |issue=3 |pages=221–228 |doi=10.1016/0025-5408(93)90155-7}}</ref>
|-
|KNiPO<sub>4</sub>{{hydrate|6}}
|potassium nickel phosphate hexahydrate
|
|monoclinic ''P''2<sub>1</sub>
|6.8309
|11.0610
|6.1165
|91.045
|462.07
|2
|
|
|<ref name="trob">{{cite journal |last1=Trobajo |first1=Camino |last2=Salvadó |first2=Miguel A. |last3=Pertierra |first3=Pilar |last4=Alfonso |first4=Belén F. |last5=Blanco |first5=Jesús A. |last6=Khainakov |first6=Serguei A. |last7=García |first7=José R. 
|title=Synthesis, Structure and Magnetic Characterization of Two Phosphate Compounds Related with the Mineral Struvite: <math chem>\ce{KNiPO4.6H2O}</math> and <math chem>\ce{NaNiPO4.7H2O}</math>
|journal=Zeitschrift für anorganische und allgemeine Chemie 
|date=September 2007 |volume=633 |issue=11–12 |pages=1932–1936 |doi=10.1002/zaac.200700342}}</ref>
|-
|NiK<sub>4</sub>(P<sub>3</sub>O<sub>9</sub>)<sub>2</sub>{{hydrate|7}}
|nickel potassium tricyclophosphate hydrate
|
|orthorhombic Fm2m
|23.03
|11.882
|8.732
|
|
|4
|
|blue
|<ref name="sbai"/>
|-
|NiK<sub>4</sub>(P<sub>3</sub>O<sub>9</sub>)<sub>2</sub>
|nickel potassium tricyclophosphate
|
|triclinic P-1
|6.143
|6.80
|12.80
|α=102.8 β=89.7 γ=66.03
|473.56
|1
|
|
|<ref name="sbai"/>
|-
|NaK<sub>5</sub>Ni<sub>5</sub>(P<sub>2</sub>O<sub>7</sub>)<sub>4</sub>
|Sodium pentapotassium pentanickel tetra(diphosphate)
|1207.80
|triclinic
|7.188
|9.282
|10.026(5)
|α=109.31 β=90.02 γ=104.07
|610.0
|1
|
|
|<ref>{{cite journal |last1=Moutataouia |first1=Meryem |last2=Lamire |first2=Mohammed |last3=Saadi |first3=Mohamed |last4=El Ammari |first4=Lahcen 
|title=Sodium pentapotassium pentanickel tetra(diphosphate), <math chem>\ce{NaK5Ni5(P2O7)3 }</math>
|journal=Acta Crystallographica Section E  
|date=12 May 2012 |volume=68 |issue=6 |pages=i43 |doi=10.1107/S160053681202017X|pmid=22719274 |pmc=3379053 }}</ref>
|-
|{{chem2|NH4NiPO4*H2O}}
|ammonium nickel phosphate hydrate
|
|orthorhombic
|5.566
|8.760
|4.742
|
|231.2
|
|
|
|<ref>{{cite journal |last1=Guerra-López |first1=J. |last2=Gómez |first2=A. |last3=Pomés |first3=R. |last4=González |first4=R. 
|title=X-ray powder diffraction data for ammonium nickel phosphate monohydrate 
|journal=Powder Diffraction 
|date=10 January 2013 |volume=10 |issue=3 |pages=152–153 |doi=10.1017/S0885715600014627|bibcode=1995PDiff..10..152G |s2cid=221940206 }}</ref>
|-
|{{chem2|NH4NiPO4*6H2O}}
|ammonium nickel phosphate hydrate<br/>Ni-struvite
|
|Orthorhombic ''Pmn''2<sub>1</sub>
|6.924
|6.104
|11.166
|
|471.5
|2
|
|
|<ref>{{cite journal |last1=Blachnik |first1=R. |last2=Wiest |first2=Th. |last3=Dülmer |first3=A. |last4=Reuter |first4=H. 
|title=The crystal structure of ammonium hexaaquanickel(II) phosphate 
|journal=Zeitschrift für Kristallographie - Crystalline Materials 
|date=1 January 1997 |volume=212 |issue=1 |page=20 |doi=10.1524/zkri.1997.212.1.20|bibcode=1997ZK....212...20B |s2cid=95454523 }}</ref><ref>{{cite journal |last1=Wu |first1=Xuehang |last2=Wu |first2=Wenwei |last3=Li |first3=Shushu |last4=Cui |first4=Xuemin |last5=Liao |first5=Sen 
|title=Kinetics and thermodynamics of thermal decomposition of <math chem>\ce{NH4NiPO4.6H2O }</math>
|journal=Journal of Thermal Analysis and Calorimetry 
|date=7 October 2010 |volume=103 |issue=3 |pages=805–812 |doi=10.1007/s10973-010-1057-5|s2cid=98277099 }}</ref><ref>{{cite journal |last1=Haferburg |first1=Götz |last2=Kloess |first2=Gert |last3=Schmitz |first3=Werner |last4=Kothe |first4=Erika 
|title="Ni-struvite" – A new biomineral formed by a nickel resistant Streptomyces acidiscabies 
|journal=Chemosphere 
|date=June 2008 |volume=72 |issue=3 |pages=517–523 |doi=10.1016/j.chemosphere.2008.02.050|pmid=18410951 |bibcode=2008Chmsp..72..517H }}</ref>
|-
|LiNiPO<sub>4</sub>
|lithium nickel phosphate
|
|orthorhombic
|10.032
|5.855
|4.681
|
|274.9
|4
|
|brown
|<ref>{{cite journal |last1=Warda |first1=S. A. |last2=Lee |first2=S.-L. 
|title=Refinement of the crystal structure of lithium nickel phosphate, <math chem>\ce{LiNiPO4 }</math>
|journal=Zeitschrift für Kristallographie - New Crystal Structures 
|date=1 January 1997 |volume=212 |issue=1 |doi=10.1524/ncrs.1997.212.1.319|doi-access=free }}</ref>
|-
|NaNiPO<sub>4</sub>
|sodium nickel phosphate
|
|''Pnma'' maricite structure
|8.7839
|6.7426
|5.0368
|
|298.31
|4
|
|yellow
|<ref name=Korch>{{cite journal |last1=Korchemkin |first1=I. V. |last2=Pet'kov |first2=I. V. |last3=Kurazhkovskaya |first3=V. S. |last4=Borovikova |first4=E. Yu. 
|title=Synthesis of sodium nickel phosphate and its crystallographic, spectroscopic, and temperature-controlled X-ray diffraction study 
|journal=Russian Journal of Inorganic Chemistry 
|date=25 March 2015 |volume=60 |issue=3 |pages=265–269 |doi=10.1134/S0036023615030092|s2cid=95193525 }}</ref>
|-
|NaNiPO<sub>4</sub>
|sodium nickel phosphate
|
|''Pnma'' triphylite form
|4.98
|6.13
|9.98
|
|304.23
|
|
|
|<ref>{{cite journal |last1=Minakshi |first1=Manickam |last2=Mitchell |first2=David |last3=Jones |first3=Rob |last4=Alenazey |first4=Feraih |last5=Watcharatharapong |first5=Teeraphat |last6=Chakraborty |first6=Sudip |last7=Ahuja |first7=Rajeev 
|title=Synthesis, structural and electrochemical properties of sodium nickel phosphate for energy storage devices 
|journal=Nanoscale 
|date=2016 |volume=8 |issue=21 |pages=11291–11305 |doi=10.1039/C6NR01179A|pmid=27189034 |bibcode=2016Nanos...811291M |url=https://researchrepository.murdoch.edu.au/id/eprint/31533/}}<!--https://researchrepository.murdoch.edu.au/id/eprint/31533/ }}--></ref>
|-
|Na<sub>4</sub>Ni<sub>7</sub>(PO<sub>4</sub>)<sub>6</sub>
|
|
|''Cm''
|10.550
|13.985
|6.398
|104.87
|912.4
|2
|3.906
|
|<ref name=Korch/><ref>{{cite journal |last1=Moring |first1=J. |last2=Kostiner |first2=E. 
|title=The crystal structure of <math chem>\ce{Na4Ni7(PO4)6 }</math>
|journal=Journal of Solid State Chemistry 
|date=March 1986 |volume=62 |issue=1 |pages=105–111 |doi=10.1016/0022-4596(86)90221-5|bibcode=1986JSSCh..62..105M }}</ref>
|-
|NaNiPO<sub>4</sub>{{hydrate|7}}
|sodium nickel phosphate heptahydrate
|
|tetrahedral ''P''4<sub>2</sub>/mmc
|6.7390
|
|10.9690
|
|498.15
|2
|
|
|<ref name=trob/>
|-
|Na<sub>3</sub>NiP<sub>3</sub>O<sub>10</sub>{{hydrate|12}}
|trisodium nickel triphosphate dodecahydrate
|
|monoclinic (pseudoorthorhombic)
|15.0236
|9.1972
|14.6654.
|90.0492
|2014.46
|
|1.967
|light green
|<ref>{{cite journal |last1=Azzaoui |first1=Khalil |last2=Essehli |first2=Rachid |last3=Mejdoubi |first3=El Miloud |last4=El Bali |first4=Brahim |last5=Dusek |first5=Michal |last6=Fejfarova |first6=Karla 
|title=<math chem>\ce{Na3MP3O10.12H2O}</math> (M=Co, Ni): Crystal Structure and IR Spectroscopy 
|journal=International Journal of Inorganic Chemistry 
|date=2012 |volume=2012 |pages=1–6 |doi=10.1155/2012/702471|doi-access=free }}</ref>
|-
|Na<sub>5</sub>Ni<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub>{{hydrate}}
|Pentasodium dinickel triphosphate hydrate
|
|monoclinic space group ''P''2<sub>1</sub>/''n''
|14.0395
|5.185
|16.4739
|110.419
|
|
|
|
|<ref name="kirs">{{cite journal |last1=Kirsanova |first1=Maria A. |last2=Aksyonov |first2=Dmitry A. |last3=Maximova |first3=Olga V. |last4=Shvanskaya |first4=Larisa V. |last5=Vasiliev |first5=Alexander N. |last6=Tsirlin |first6=Alexander A. |last7=Abakumov |first7=Artem M. 
|title=Crystal Structures and Low-Dimensional Ferromagnetism of Sodium Nickel Phosphates <math chem>\ce{Na5Ni2(PO4)3.H2O}</math> and <math chem>\ce{Na6Ni2(PO4)3OH}</math>
|journal=Inorganic Chemistry 
|date=19 December 2018 |volume=58 |issue=1 |pages=610–621 |doi=10.1021/acs.inorgchem.8b02791|pmid=30565920 |s2cid=56478994 }}</ref>
|-
|Na<sub>6</sub>Ni<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub>OH
|
|
|orthorhombic ''Pcmb''
|7.501
|21.4661
|7.173
|
|
|
|
|
|<ref name=kirs/>
|-
|Na<sub>2</sub>Ni<sub>3</sub>(OH)<sub>2</sub>(PO<sub>4</sub>)<sub>2</sub>
|sodium nickel hydroxide phosphate
|
|monoclinic
|14.259
|5.695
|4.933
|104.28
|
|2
|3.816
|
|<ref>{{cite journal |last1=Yakubovich |first1=O |last2=Kiriukhina |first2=G |last3=Dimitrova |first3=O |last4=Volkov |first4=A |last5=Golovanov |first5=A |last6=Volkova |first6=O |last7=Zvereva |first7=E |last8=Baidya |first8=S |last9=Saha-Dasgupta |first9=T |last10=Vasiliev |first10=A 
|title=Crystal structure and magnetic properties of a new layered sodium nickel hydroxide phosphate, <math chem>\ce{Na2Ni3(OH)2(PO4)2}</math>. 
|journal=Dalton Transactions  
|date=1 October 2013 |volume=42 |issue=41 |pages=14718–14725 |doi=10.1039/c3dt51657a |pmid=23877251}}</ref>
|-
|NiNa<sub>4</sub>(P<sub>3</sub>O<sub>9</sub>)<sub>2</sub>{{hydrate|6}}
|nickel tetrasodium cyclotriphosphate hexahydrate
|
|triclinic
|6.157
|6.820
|10.918
|α=80.21 β=97.8 γ=119.5
|409.8
|1
|
|
|<ref>{{cite journal |author=Kacem Sbai |author2=Azzeddine Atibi |author3=Addelkrim Charaf |author4=Mohamed Radid |author5=A. Jouini 
|title=Etude des spectres vibrationnels et des proprietes physico-chimiques du cyclotriphosphate mixte de nickel et de sodium hexahydrate, <math chem>\ce{NiNa4(P3O9)2.6H2O}</math>
|journal=Annales de Chimie Science des Matériaux |volume=26 |issue=6 |year=2001 |pages=45–61 |issn=0151-9107 
|language=fr |doi=10.1016/s0151-9107(01)80098-2}}</ref>
|-
|NiRb<sub>4</sub>(P<sub>3</sub>O<sub>9</sub>)<sub>2</sub>
|nickel tetrarubidium cyclotriphosphate
|
|P-31c
|7.288
|7.288
|20.343
|
|
|2
|
|
|<ref>{{cite journal |last1=Tridane |first1=M. |last2=Belaaouad |first2=S. |last3=Sbai |first3=K. 
|title=Chemical preparations and crystal data for eight new condensed phosphates 
|journal=Solid State Sciences 
|date=November 2000 |volume=2 |issue=7 |pages=701–704 |doi=10.1016/S1293-2558(00)01081-5|bibcode=2000SSSci...2..701T }}</ref>
|-
|NiCs<sub>4</sub>(P<sub>3</sub>O<sub>9</sub>)<sub>2</sub>{{hydrate|6}}
|nickel tetracaesium cyclotriphosphate hydrate
|
|orthorhombic 
|19.992
|6.500
|18.445
|
|
|4
|
|
|<ref name="sbai">{{cite journal |last1=Sbai |first1=Kacem |last2=Atibi |first2=Azeddine |last3=Kenz |first3=Abdelkebir |last4=Tace |first4=Elmostafa |last5=Tridane |first5=Malika 
|title=CHEMICAL PREPARATION AND CRYSTAL DATA FOR TWO CONDENSED PHOSPHATES NiCs<SUB>4</SUB>(PO<SUB>3</SUB>)<SUB>6</SUB> AND NiK<SUB>4</SUB>(P<SUB>3</SUB>O<SUB>9</SUB>)<SUB>2</SUB> 
|journal=Phosphorus Research Bulletin 
|date=2003 |volume=16 |pages=107–111 |doi=10.3363/prb1992.16.0_107 
|url=https://www.jstage.jst.go.jp/article/prb1992/16/0/16_107/_pdf|doi-access=free }}</ref>
|-
|NiCs<sub>4</sub>(PO<sub>3</sub>)<sub>6</sub>
|nickel tetracaesium cyclotriphosphate
|
|rhombohedral P-3<sub>1</sub>c
|11.602
|11.602
|9.078
|
|1058.24
|2
|
|
|<ref name="sbai"/>
|-
|NiAg<sub>4</sub>(P<sub>3</sub>O<sub>9</sub>)<sub>2</sub>{{hydrate|6}}
|nickel tetrasilver cyclotriphosphate hexahydrate
|
|triclinic
|9.209
|8.053
|6.841
|α=89.15 β=102.94 γ=97.24
|
|1
|
|
|<ref name="sbai02">{{cite journal |last1=Sbai |first1=Kacem |last2=Atibi |first2=Azzeddine |last3=Belaaouad |first3=Saïd |last4=Moutaabid |first4=Mohamed 
|title=Etude Des Proprietes Physico-Chimiques du Cyclotriphosphate Mixte de Nickel et D'argent Hexahydrate, <math chem>\ce{NiAg4(P3O9)2.6H2O}</math>
|journal=Phosphorus, Sulfur, and Silicon and the Related Elements 
|date=October 2002 |volume=177 |issue=10 |pages=2345–2362 |doi=10.1080/10426500214290|s2cid=94289865 }}</ref>
|-
|NiAg<sub>4</sub>(P<sub>3</sub>O<sub>9</sub>)<sub>2</sub>
|nickel tetrasilver cyclotriphosphate
|
|triclinic
|6.100
|6.783
|10.764
|α = 78.66 β=96.85 γ=113.36
|401
|1
|
|
|<ref name="sbai02"/>
|-
|Ni(NH<sub>4</sub>)<sub>4</sub>(P<sub>3</sub>O<sub>9</sub>)<sub>2</sub>{{hydrate|4}}
|nickel tetraammonium cyclotriphosphate tetrahydrate
|
|monoclinic
|
|
|
|
|
|2
|
|
|<ref>{{cite journal |last1=Ezzaafrani |first1=M. |last2=Ennaciri |first2=Abdelaziz |last3=Harcharras |first3=Mohamed |last4=Khaoulaf |first4=Redouane |last5=Capitelli |first5=Francesco 
|title=Crystal structure and infrared spectrum of new magnesium tetra-ammonium cyclotriphosphate tetrahydrate <math chem>\ce{Mg(NH4 )4(P3O9)2. 4 H2O}</math>
|journal=Zeitschrift für Kristallographie 
|date=March 2012 |volume=227 |issue=3 |pages=141–146 |doi=10.1524/zkri.2012.1472|bibcode=2012ZK....227..141E |s2cid=100862854 }}</ref>
|-
|TlNi<sub>4</sub>(PO<sub>4</sub>)<sub>3</sub>
|Thallium nickel triphosphate
|
|orthorhombic Cmc2<sub>1</sub>
|
|
|
|
|
|4
|
|pale yellow
|<ref name=jung/>
|-
|Tl<sub>4</sub>Ni<sub>6</sub>(PO<sub>4</sub>)<sub>6</sub>
|Thallium nickel hexaphosphate
|
|monoclinic Cm
|
|
|
|
|
|4
|
|yellow brown
|<ref name=jung/>
|-
|Tl<sub>2</sub>Ni<sub>4</sub>P<sub>2</sub>O<sub>7</sub>(PO<sub>4</sub>)<sub>2</sub>
|
|
|monoclinic C2/c
|
|
|
|
|
|8
|
|brown
|<ref name="jung">{{cite journal |last1=Panahandeh |first1=Ahmad |last2=Jung |first2=Walter 
|title=The Oxidation of Heterogeneous Tl/Ni/P-Alloys— Preparation and Crystal Structures of the Thallium Nickel Phosphates <math chem>\ce{TlNi4(PO4)3, Tl4Ni7(PO4)6}</math>, and <math chem>\ce{Tl2Ni4(P2O7)(PO4)2}</math>
|journal=Zeitschrift für anorganische und allgemeine Chemie 
|date=September 2003 |volume=629 |issue=10 |pages=1651–1660 |doi=10.1002/zaac.200300133}}</ref>
|-
|NiMnSb
|Nickel manganese antimonide
|
|cubic
|5.945
|
|
|
|210.1
|4
|7.57
|
|<ref>{{cite web 
|title=NiMnSb (MnNiSb) Crystal Structure - SpringerMaterials 
|url=http://materials.springer.com/isp/crystallographic/docs/sd_0558354 |website=materials.springer.com}}</ref>
|-
|NiMnSi
|Nickel manganese silicide
|
|Orthorhombic
|5.8967
|3.6124
|6.9162
|
|147.32
|4
|
|
|<ref>{{cite journal |last1=Zhang |first1=Rui-Jing |last2=Eckern |first2=Ulrich |last3=Schwingenschlögl |first3=Udo 
|title=Fate of Half-Metallicity Near Interfaces: The Case of NiMnSb/MgO and NiMnSi/MgO 
|journal=ACS Applied Materials & Interfaces 
|date=27 August 2014 |volume=6 |issue=16 |pages=14516–14521 |doi=10.1021/am5037753|pmid=24998299 |arxiv=1403.0889 |s2cid=206802328 }}</ref><ref name="Johnso">{{cite journal |last1=Johnson |first1=V. 
|title=Diffusionless orthorhombic to hexagonal transitions in ternary silicides and germanides 
|journal=Inorganic Chemistry 
|date=May 1975 |volume=14 |issue=5 |pages=1117–1120 |doi=10.1021/ic50147a032}}</ref>
|-
|NiMnGe
|
|
|orthorhombic Pnma
|6.053
|3.769
|7.090
|
|161.75
|2
|
|
|<ref name=Bazela>{{cite journal |last1=Bazela |first1=W. |last2=Szytuła |first2=A. |last3=Todorović |first3=J. |last4=Tomkowicz |first4=Z. |last5=Zięba |first5=A. 
|title=Crystal and magnetic structure of NiMnGe 
|journal=Physica Status Solidi A 
|date=16 December 1976 |volume=38 |issue=2 |pages=721–729 |doi=10.1002/pssa.2210380235|bibcode=1976PSSAR..38..721B }}</ref>
|-
|NiFeGe
|
|
|hexagonal
|
|
|
|
|
|
|
|
|<ref name=Bazela/>
|-
|TiNiSi
|
|
|orthorhombic
|
|
|
|
|
|
|
|
|<ref name=Bazela/>
|-
|NaNiIO<sub>6</sub>
|sodium nickel periodate
|
|orthorhombic
|8.599
|2.492
|10.281
|
|220.3
|
|
|
|<ref name=r11>{{cite web 
|title=Соединения Ni (тома 11-14) 
|url=http://www.kipt.kharkov.ua/kipt_sites/isspmst/crystal/ni/ni11-14.html |access-date=28 July 2016}}</ref>
|-
|KNiIO<sub>6</sub>
|potassium nickel periodate
|
|orthorhombic
|12.09
|3.683
|6.062
|
|269.9
|
|
|
|<ref name=r11/>
|-
|KNiIO<sub>6</sub>
|potassium nickel periodate
|
|triclinic
|6.4203
|5.075
|4.223
|α= 65.07 β= 92.717 γ=109.95
|116.51
|
|
|
|<ref name=r11/>
|}

Double fluorides include the above-mentioned fluoroanion salts, and those [[fluoronickelate]]s such as NiF<sub>4</sub> and NiF<sub>6</sub>. Other odd ones include an apple green coloured KNiF<sub>3</sub>·H<sub>2</sub>O and NaNiF<sub>3</sub>·H<sub>2</sub>O, aluminium nickel pentafluoride AlNiF<sub>5</sub>·7H<sub>2</sub>O, ceric nickelous decafluoride Ce<sub>2</sub>NiF<sub>10</sub>·7H<sub>2</sub>O, niobium nickel fluoride Ni<sub>3</sub>H<sub>4</sub>Nb<sub>2</sub>F<sub>20</sub>·19H<sub>2</sub>O, vanadium nickel pentafluoride VNiF<sub>5</sub>·7H<sub>2</sub>O, vanadyl nickel tetrafluoride VONiF<sub>4</sub>·7H<sub>2</sub>O, chromic nickelous pentafluoride CrNiF<sub>5</sub>·7H<sub>2</sub>O, molybdenum nickel dioxytetrafluoride NiMoO<sub>2</sub>F<sub>4</sub>·6H<sub>2</sub>O, tungsten nickel dioxytetrafluoride NiWO<sub>2</sub>F<sub>4</sub>·6H<sub>2</sub>O and NiWO<sub>2</sub>F<sub>4</sub>·10H<sub>2</sub>O, manganic nickel pentafluoride MnNiF<sub>4</sub>·7H<sub>2</sub>O, nickelous ferric fluoride FeNiF<sub>5</sub>·7H<sub>2</sub>O.<ref>Mellor 405-406</ref>

Nickel trichloride double salts exist which are polymers. Nickel is in octahedral coordination, with double halogen bridges. Examples of this include RbNiCl<sub>3</sub>, pinkish tan coloured H<sub>2</sub>NN(CH<sub>3</sub>)<sub>3</sub>NiCl<sub>3</sub>.<ref>{{cite journal |last1=Goedken |first1=V. L. |last2=Vallarino |first2=L. M. |last3=Quagliano |first3=J. V. 
|title=Cationic ligands. Coordination of the 1,1,1-trimethylhydrazinium cation to nickel(II) 
|journal=Inorganic Chemistry 
|date=December 1971 |volume=10 |issue=12 |pages=2682–2685 |doi=10.1021/ic50106a011}}</ref> Other double trichlorides include potassium nickel trichloride KNiCl<sub>3</sub>·5H<sub>2</sub>O,<ref name=m419/> yellow cesium nickel trichloride CsNiCl<sub>3</sub>,<ref name=m419/> lithium nickel trichloride LiNiCl<sub>3</sub>·3H<sub>2</sub>O,<ref name=m419/> hyrdrazinium nickel tetrachloride,<ref name=m419/> and nickel ammonium chloride hexahydrate NH<sub>4</sub>NiCl<sub>3</sub>·6H<sub>2</sub>O.<ref name="CRC">{{cite book |editor1-last=Haynes |editor1-first=W. M. |title=CRC Handbook of Chemistry and Physics 
|date=2014 |isbn=978-1-4822-0867-2 |pages=4–77–4–78 |publisher=CRC Press |edition=95}}</ref>

The [[tetrachloronickelates]] contain a tetrahedral NiCl<sub>4</sub><sup>2−</sup> and are dark blue. Some salts of organic bases are ionic liquids at [[standard conditions]].<ref name="Meredith">{{cite journal |last1=Meredith |first1=M. Brett |last2=McMillen |first2=C. Heather |last3=Goodman |first3=Jonathan T. |last4=Hanusa |first4=Timothy P. 
|title=Ambient temperature imidazolium-based ionic liquids with tetrachloronickelate(II) anions 
|journal=Polyhedron 
|date=August 2009 |volume=28 |issue=12 |pages=2355–2358 |doi=10.1016/j.poly.2009.04.037}}</ref> tetramethylammonium nickel trichloride is pink and very insoluble.<ref>{{cite journal |last1=Cotton |first1=F. A. |last2=Faut |first2=O. D. |last3=Goodgame |first3=D. M. L. 
|title=Preparation, Spectra and Electronic Structures of Tetrahedral Nickel(II) Complexes Containing Triphenylphosphine and Halide Ions as Ligands 
|journal=Journal of the American Chemical Society 
|date=January 1961 |volume=83 |issue=2 |pages=344–351 |doi=10.1021/ja01463a021}}</ref>
Other tetrachlorides include rubidium nickel tetrachloride, lithium nickel tetrachloride Li<sub>2</sub>NiCl<sub>4</sub>·4H<sub>2</sub>O stable from 23 to 60°, stannous nickel tetrachloride <math chem>\ce{SnCl2.NiCl2.6H2O}</math>, stannic nickel hexachloride <math chem>\ce{SnCl4.NiCl2.6H2O}</math> is tetragonal.<ref name=m420/>

Lithium nickel hexachloride Li<sub>4</sub>NiCl<sub>6</sub>·10H<sub>2</sub>O is stable from 0 to 23°.

Copper nickel dioxychloride 2CuO·NiCl<sub>2</sub>·6H<sub>2</sub>O, and copper nickel trioxychloride 3CuO·NiCl<sub>2</sub>·4H<sub>2</sub>O.<ref name=m419>Mellor p419</ref>

Cadmium dinickel hexachloride, <math chem>\ce{CdCl2.2NiCl2.12H2O}</math> crystallises in hexagonal system, dicadmium dinickel hexachloride, <math chem>\ce{2CdCl2.NiCl2.12H2O}</math> has rhombic crystals, and is [[pleochroic]] varying from light to dark green.<ref name=m420>Mellor p420</ref>

Thallic nickel octochloride <math chem>\ce{2TlCl3.NiCl2.8H2O}</math> is bright green.<ref name=m420/>

Double bromides include the [[tetrabromonickelates]], and also caesium nickel tribromide, CsNiBr<sub>3</sub>
copper nickel trioxybromide, 3CuO·NiBr<sub>2</sub>·4H<sub>2</sub>O
mercuric nickel bromide, Hg<sub>2</sub>NiBr6, HgNiBr<sub>4</sub>.
Aqueous nickel bromide reacting with mercuric oxide yields mercuric nickel oxybromide, <math chem>\ce{6NiO.NiBr2.HgBr2.20H2O}</math>
didymium nickel bromide, <math chem>\ce{2(Pr,Nd)Br3.3NiBr2.18H2O}</math> is reddish brown (mixture of praseodymium and neodymium)
Lanthanum nickel bromide, <math chem>\ce{2LaBr3.3NiBr2.18H2O}</math>
nickel stannic bromide (or nickel bromostannate) NiSnBr<sub>6</sub>·8H<sub>2</sub>O is apple green.<ref>{{cite journal 
|title=Inorganic chemistry Abstracts 
|journal=Journal of the Chemical Society, Abstracts 
|date=1884 |volume=46 |page=1254 |doi=10.1039/CA8844601254}}</ref><ref>Mellor 457</ref>

The [[tetraiodonickelates]] are blood red coloured salts of the NiI<sub>4</sub> ion with large cations. Double iodides known include mercuric nickel hexaiodide 2HgI<sub>2</sub>•NiI<sub>2</sub>{{hydrate|6}}, mercuric nickel tetraiodide HgI<sub>2</sub>•NiI<sub>2</sub>{{hydrate|6}}, and lead nickel hexaiodide I<sub>2</sub>•2NiI<sub>2</sub>{{hydrate|3}}.<ref name=mellor>{{cite book |last1=Mellor |first1=J. W. |chapter=Nickel 
|title=A Comprehensive Treatise on Inorganic and Theoretical Chemistry Volume XV Ni Ru, Rh Pd, Os, Ir 
|chapter-url=https://archive.org/details/b2980789x_0015/ |access-date=17 January 2019 
|date=1946}}</ref>

The [[diperiodatonickelates]] of nickel IV are strong oxidisers, and akali monoperiodatonickelates also are known.

Nickel forms double nitrates with the lighter rare earth elements. The solid crystals have the formula <math chem>\ce{Ni3Me2(NO3)12.24H2O}</math>. The metals include La Ce Pr Nd Sm Gd and the non rare earth Bi. Nickel can also be replaced by similar divalent ions, Mg, Mn Co Zn. For the nickel salts melting temperatures range from 110.5° for La, 108.5° for Ce, 108° for Pr, 105.6° for Nd, 92.2° for Sm and down to 72.5° for Gd The Bi salt melting at 69°. Crystal structure is hexagonal with Z=3.<ref>{{cite journal |last1=Jantsch |first1=G. 
|title=Zur Kenntnis der Doppelnitrate der seltenen Erden. II. Mitteilung 
|journal=Zeitschrift für anorganische Chemie 
|date=11 June 1912 |volume=76 |issue=1 |pages=303–323 |doi=10.1002/zaac.19120760112|url=https://zenodo.org/record/1428132 
}}</ref> <math chem>\ce{Ni3La2(NO3)12.24H2O}</math> becomes [[Ferromagnetism|ferromagnetic]] below 0.393&nbsp;K.<ref>{{cite journal |last1=Mess |first1=K.W. |last2=Lagendijk |first2=E. |last3=Zimmerman |first3=N.J. |last4=Van Duyneveldt |first4=A.J. |last5=Giesen |first5=J.J. |last6=Huiskamp |first6=W.J. 
|title=Magnetic and caloric study of the phase transitions of copper, nickel, manganese and cobalt lanthanum double nitrate 
|journal=Physica 
|date=July 1969 |volume=43 |issue=2 |pages=165–208 |doi=10.1016/0031-8914(69)90001-9|bibcode=1969Phy....43..165M }}</ref> These double nickel nitrates have been used to separate the rare earth elements by [[fractional crystallization (chemistry)|fractional crystallization]].<ref>{{cite journal |last1=Urbain |first1=G. 
|title=Sur une terre yttrique voisine du gadolinium 
|journal=Comptes rendus hebdomadaires des séances de l'Académie des sciences 
|date=1 July 1904 |volume=139 |issue=7 |pages=736–738 
|url=http://gallica.bnf.fr/ark:/12148/bpt6k30930/f736.image.r=|access-date=14 July 2016}}</ref>

Nickel thorium nitrate has formula NiTh(NO<sub>3</sub>)<sub>6</sub>{{hydrate|8}}. Nickel atoms can be substituted by other ions with radius 0.69 to 0.83&nbsp;Å. The nitrates are coordinated on the thorium atom and the water to the nickel. Enthalp of solution of the octahydrate is 7 kJ/mol. Enthalpy of formation is -4360 kJ/mol. At 109° the octahydrate becomes <math chem>\ce{NiTh(NO3)6.6H2O}</math>, and at 190° <math chem>\ce{NiTh(NO3)6.3H2O}</math> and anhydrous at 215°.<ref name="Cherno">{{cite journal |last1=Chernorukov |first1=N. G. |last2=Knyazev |first2=A. V. |last3=Sazonov |first3=A. A. 
|title=Synthesis, structure, and physicochemical properties of bivalent element hexanitratothorates 
|journal=Radiochemistry 
|date=11 October 2009 |volume=51 |issue=5 |pages=437–440 |doi=10.1134/S1066362209050014|s2cid=98032208 }}</ref>
The hexahydrate has ''Pa''{{overline|3}} cubic structure.<ref name="Cherno"/>

Various double amides containing nickel clusters have been made using liquid ammonia as a solvent. Substances made include red Li<sub>3</sub>Ni<sub>4</sub>(NH<sub>2</sub>)<sub>11</sub>·NH<sub>3</sub> (Pna21; Z = 4; a = 16.344(3) Å; b = 12.310(2) Å; c = 8.113(2) Å v=1631 D=1.942), and Cs<sub>2</sub>Ni(NH<sub>2</sub>)<sub>4</sub>•NH<sub>3</sub> (P21/c; Z = 4; a =9.553(3) Å; b = 8.734(3) Å; c = 14.243(3) Å; β = 129.96(3)° V=910 D=2.960). These are called amidonickel compounds.<ref name="tenten">{{cite journal |last1=Tenten |first1=A. |last2=Jacobs |first2=H. 
|title=Substitutionsvarianten von Nickel(II) amid: ternäre amidoniccolate mit Lithium und Caesium <math chem>\ce{Li3Ni4(NH2)11.NH3}</math> und <math chem>\ce{Cs2Ni(NH2)4.NH3}</math>
|journal=Journal of Alloys and Compounds 
|date=December 1991 |volume=177 |issue=2 |pages=193–217 |doi=10.1016/0925-8388(91)90074-6}}</ref> Yet others include Li<sub>4</sub>Ni<sub>4</sub>(NH<sub>2</sub>)<sub>12</sub>·NH<sub>3</sub>, Na<sub>2</sub>Ni(NH<sub>2</sub>)<sub>4</sub>,<ref>{{cite journal |last1=Jacobs |first1=Herbert |last2=Niewa |first2=Rainer |last3=Sichla |first3=Thomas |last4=Tenten |first4=Andreas |last5=Zachwieja |first5=Uwe 
|title=Metal nitrogen compounds with unusual chemical bonding: nitrides, imides, amides and ammine complexes 
|journal=Journal of Alloys and Compounds 
|date=January 1997 |volume=246 |issue=1–2 |pages=91–100 |doi=10.1016/S0925-8388(96)02458-9}}</ref> orange red Na<sub>2</sub>Ni(NH<sub>2</sub>)<sub>4</sub>•2NH<sub>3</sub>,<ref>{{cite journal |last1=Tenten |first1=A. |last2=Jacobs |first2=H. 
|title=Partielle Substitution von Nickel durch Natrium in Nickel(II)-amid: Isolierte <math chem>\ce{Na4Ni2(NH2)8.4NH3}</math>-Einheiten in Natriumtetraamidoniccolat(II)-diammoniakat 
|journal=Zeitschrift für anorganische und allgemeine Chemie 
|date=October 1991 |volume=604 |issue=1 |pages=113–126 |language=de |doi=10.1002/zaac.19916040115}}</ref> Na<sub>2</sub>Ni(NH<sub>2</sub>)<sub>4</sub>•NH<sub>3</sub>, K<sub>2</sub>Ni(NH<sub>2</sub>)<sub>4</sub>•0.23KNH<sub>2</sub>, and Rb<sub>2</sub>Ni(NH<sub>2</sub>)<sub>4</sub>•0.23RbNH<sub>2</sub>.<ref name=tenten/>

Nickel dihydrogen phosphide (Ni(PH<sub>2</sub>)<sub>2</sub>) can form orange, green or black double salts KNi(PH<sub>2</sub>)<sub>3</sub>) that crystallise from liquid ammonia. They are unstable above -78&nbsp;°C, giving off [[ammonia]], [[phosphine]] and hydrogen.<ref>{{cite journal |last1=Schmitz-DuMont |first1=O. |last2=Uecker |first2=G. |last3=Schaal |first3=W. 
|title=Dihydrogenphosphide und Dihydrogenphosphidosalze der Übergangsmetalle. I. Nickel(II)-dihydrogenphosphid und Kalium-tris-[dihydrogen-phosphido]-niccolat (II) 
|journal=Zeitschrift für anorganische und allgemeine Chemie 
|date=October 1969 |volume=370 |issue=1–2 |pages=67–79 |doi=10.1002/zaac.19693700108}}</ref>

==References==
<references />

[[Category:Nickel compounds]]
[[Category:Double salts]]