# Oxalate sulfate

Oxalate sulfates are mixed anion compounds containing oxalate and sulfate. They are mostly transparent, and any colour comes from the cations.
Related compounds include the sulfite oxalates and oxalate selenates.

## Production

Oxalate sulfates may be deposited from a solution in water of the metal anions and sulfate with oxalic acid when evaporated. Crystals formed this way may be hydrates.

## Properties

Many crystal forms are non-centrosymmetric and have non-linear optical properties.
When heated, oxalate sulfates will first dehydrate, and then give off carbon dioxide.

## List

| name | formula | system | space group | unit cell Å | volume | density | comment |
| lithium sulfate monohydrate oxalate | ? | triclinic | P1 | a = 3.4014 b = 5.0397 c = 6.120 α = 78.62° β= 84.95° γ = 81.14° | 101.45 | | band gap 4.57 eV dielectric constant 29.7 stable below 83 °C piezoelectric coefficient 6pC/N |
| homopiperazinium dimagnesium dioxalate sulfate dihydrate | C$_5$H$_{14}$N$_2$•Mg$_2$•[C$_2$O$_4$]$_2$•SO$_4$•2H$_2$O | monoclinic | Ia | a=11.5673 b=27.3352 c=16.6097 β=95.255° Z=12 | 5229.8 | 1.749 | colourless |
| piperazinium magnesium oxalate sulfate hydrate | C$_4$H$_{12}$N$_2$•Mg•[C$_2$O$_4$]•SO$_4$•H$_2$O | monoclinic | P2$_1$/c | a=12.7330 b=8.9240 c=11.8172 β=115.502° Z=4 | 1211.95 | 1.724 | colourless |
| potassium sulphato oxalate | ? | triclinic | | a = 6.37 b = 7.03 c = 10.61 α = 93.96 ̊ β = 101.37 ̊ γ = 100.1 ̊ | | | colourless > 300 nm; SHG 1.6×KDP |
| bapp = 1,4-bis(3-aminopropyl)piperazine | (H$_4$bapp)$_{0.5}$·VO(SO$_4$)(C$_2$O$_4$) | triclinic | P1 | a=6.2031 b=8.6599 c=12.1853 α=77.130° β=76.207° γ=82.987° | | | |
| bipy=4,4′-bipyridine; (μ$_2$-Oxalato-O,O',O'',O''')-tetrakis(2,2'-bipyridine)-di-chromium(iii) disulfate 2,2'-bipyridine solvate monohydrate | [Cr$_2$(bipy)$_4$(C$_2$O$_4$)](SO$_4$)·(bipy)$_{0.5}$·H$_2$O | triclinic | P1 | a=11.610 b=12.668 c=17.155 α=77.297° β=83.957° γ=85.458° | | | |
| depa = 3-(diethylamino)propylamine | H$_2$depa⋅Mn$_2$(SO$_4$)(C$_2$O$_4$)$_2$(H$_2$O)⋅H$_2$O | orthorhombic | Pbca | a=14.6293 b=15.6671 c=17.3579 | | | |
| hpip = homopiperazine | H$_2$hpip·Mn$_2$(SO$_4$)(C$_2$O$_4$)$_2$(H$_2$O) | orthorhombic | P2$_1$2$_1$2$_1$ | a=9.9066 b=12.4496 c=13.6640 | | | |
| pip = piperazine; piperazinediium (μ-oxalato)-bis(μ-sulfato)-diaqua-di-manganese(ii) dihydrate | H$_2$pip·Mn$_2$(SO$_4$)$_2$(C$_2$O$_4$)(H$_2$O)$_4$ | triclinic | P1 | a 6.6501(4)Å b 7.7034(4)Å c 9.6810(5)Å, α 69.850(4)° β 70.553(5)° γ 83.921(4)° | | | |
| ipa = 3,3′-iminobis(N,N-dimethylpropylamine) bis(3-dimethylammoniopropyl)ammonium pentakis(μ-oxalato)-bis(μ-sulfato)-tetra-manganese(ii) dihydrate | H$_3$ipa⋅Mn$_2$(SO$_4$)(C$_2$O$_4$)$_{2.5}$·H$_2$O | triclinic | P1 | a 9.9379(6)Å b 11.2423(6)Å c 11.6390(7)Å, α 86.793(5)° β 81.644(5)° γ 74.481(5)° | | | |
| dpta = dipropylenetriamine; bis(3-ammoniopropyl)ammonium tris(μ-oxalato)-bis(μ-sulfato)-bis(sulfato)-hexa-aqua-tetra-manganese(ii) | H$_3$dpta⋅Mn$_2$(SO$_4$)$_2$(C$_2$O$_4$)$_{1.5}$(H$_2$O)$_3$ | triclinic | P1 | a 8.6819(3)Å b 10.1689(3)Å c 13.7456(5)Å, α 70.197(3)° β 73.406(3)° γ 87.636(3)° | | | |
| dmen = N,N-dimethylethylenediamine | H$_2$dmen·Mn(SO$_4$)(C$_2$O$_4$) | monoclinic | P2$_1$/n | a=9.8603 b=12.6525 c=10.0837 β=113.002° | | | |
| bis(N,N-dimethylpropane-1,3-diaminium) bis(μ-oxalato)-bis(μ-sulfato)-di-manganese | | triclinic | P1 | a=8.5307 b=9.0432 c=9.6913 α=69.632° β=64.639° γ=88.148° | | | |
| butane-1,4-diaminium bis(μ-oxalato)-(μ-sulfato)-aqua-di-manganese | | triclinic | P1 | a=8.5468 b=10.0050 c=10.6532 α=75.445° β=79.787° γ=71.848° | | | |
| | Na$_2$Fe(C$_2$O$_4$)SO$_4$⋅H$_2$O | | | | | | orange; most air sensitive |
| (μ-oxalato)-(μ-sulfato)-iron-di-potassium | K$_2$[Fe(C$_2$O$_4$)(SO$_4$)] | monoclinic | P2$_1$/c | a=5.8735 b=10.2169 c=13.1491 β=91.226° | | | |
| tris(μ-oxalato)-bis(μ-sulfato)-tri-iron-tetra-potassium | K$_4$[Fe$_3$(C$_2$O$_4$)$_3$(SO$_4$)$_2$] | monoclinic | P2$_1$/c | a 13.739 b 5.496 c 12.774 β 97.677° | | | |
| acid oxalo-bisulfate of roseocobalt ?? | Co$_2$(HN$_3$)$_{10}$(C$_2$O$_4$)(SO$_4$)$_2$ ·H$_2$O·H$_2$C$_2$O$_4$ | | | | | | speculative |
| | [Co(NH$_3$)$_4$(C$_2$O$_4$)]$_2$SO$_4$·2H$_2$O | | | | | | |
| | [Co(NH$_3$)$_4$(C$_2$O$_4$)]$_2$S$_2$O6 | | | | | | |
| tris(μ-aqua)-tris(μ-oxalato)-tris(μ-sulfato)-tri-cobalt-hexa-sodium | Na$_2$[Co(C$_2$O$_4$)(SO$_4$)]·H$_2$O | hexagonal | P6$_2$m | a=10.2322 c=6.4774 | | | |
| tris(μ-oxalato)-bis(μ-sulfato)-bis(2-((2-aminoethyl)amino)ethanaminium)-tetraaqua-tetra-cobalt | | triclinic | P1 | a=8.6065 b=9.5595 c=9.5987 α=77.884° β=82.744° γ=87.356° | | | |
| bis(μ-oxalato)-bis(μ-sulfato)-bis(4-(2-aminoethyl)piperazin-1-ium)-tri-cobalt | | triclinic | P1 | a=8.4331 b=9.4691 c=9.5144 α=71.522° β=64.356° γ=89.622° | | | |
| 1,4-dimethylpiperazinedi-ium bis(μ-oxalato)-hepta-aqua-tri-cobalt bis(sulfate) | (H$_2$dmp)(SO$_4$)$_3$Co$_3$(C$_2$O$_4$)$_2$(H$_2$O)$_7$ | orthorhombic | Pnma | a=11.1050 b=16.4221 c=13.9815 | | | violet |
| Bis[tris(oxamide dioxime-$^2$N,N')cobalt(III)] oxalate bis(sulfate) dodecahydrate | [Co(C$_2$H$_6$N$_4$O$_2$)$_3$]$_2$(C$_2$O$_4$)(SO$_4$)$_2$12H$_2$O | triclinic | P1 | a = 9.430 b = 11.782 c = 12.812 α = 65.494° β = 83.088° γ = 86.735° Z=1 | 1285.7 | 1.698 | at 193K; red |
| homopiperazinium dizinc dioxalate sulfate hydrate | C$_5$H$_{14}$N$_2$•Zn$_2$•[C$_2$O$_4$]$_2$•SO$_4$•H$_2$O | monoclinic | P2$_1$ | a=15.8356 b=13.5022 c=15.9578 β=109.075° Z=8 | 3224.7 | 2.154 | colourless |
| homopiperazinium dizinc dioxalate sulfate dihydrate | C$_5$H$_{14}$N$_2$•Zn$_2$•[C$_2$O$_4$]$_2$•SO$_4$•2H$_2$O | monoclinic | Ia | a=11.5681 b=27.1755 c=16.5979 β=94.946° Z=12 | 5198.4 | 2.074 | colourless |
| bis(4-(2-aminoethyl)piperazin-1-ium)-bis(μ-oxalato)-bis(μ-sulfato)-tri-zinc | | triclinic | P1 | a=8.407 b=9.523 c=9.543 α=108.39° β=115.52° γ=90.17° | | | |
| 1,4-dimethylpiperazinedi-ium bis(sulfate) bis(μ-oxalato)-hepta-aqua-tri-zinc | (H$_2$dmp)(SO$_4$)$_3$Zn$_3$(C$_2$O$_4$)$_2$(H$_2$O)$_7$ | orthorhombic | Pnma | a 11.1058 b 16.3449 c 14.0064 | | | colourless |
| | (Hgly)$_2$·Zn(SO$_4$)(C$_2$O$_4$) | monoclinic | C2 | a 19.1509 b 5.4000 c 12.8206 β 102.878° | | | |
| | RbFe(SO$_4$)(C$_2$O$_4$)$_{0.5}$·H$_2$O | monoclinic | P2$_1$/c | a = 7.9193, b = 9.4907, c = 8.8090, β = 95.180°, Z = 4 | | | |
| bis(μ$_3$-sulfato)-bis(μ$_2$-oxalato)-diaqua-di-yttrium diammonium | [NH$_4$][Y(H$_2$O)(SO$_4$)(C$_2$O$_4$)] | monoclinic | P2$_1$/n | a=6.534 b=8.527 c=13.745 β=92.87° | | | |
| bis(μ$_3$-Sulfato-O,O,O',O'',O''')-(μ$_2$-oxalato-O,O',O'',O''')-(μ$_2$-piperazine-diium-1,4-diacetato-O,O')-diaqua-di-yttrium(iii) | Y$_2$(H$_2$pda)(C$_2$O$_4$)(SO$_4$)$_2$(H$_2$O)$_2$] | monoclinic | C2/c | a 19.392 b 6.2757 c 16.999 β 108.279° | | | |
| levinsonite-(Y) | (Y,Nd,Ce)Al(SO$_4$)$_2$(C$_2$O$_4$) · 12H$_2$O | monoclinic | P2/n | a = 10.289 Å, b = 9.234, c = 11.015 β = 108.50° | 992.4 | 2.181 | Biaxial (+) Refractive index: n$_α$ = 1.480 n$_β$ = 1.490 n$_γ$ = 1.550 |
| thfa = tetrahydrofurfurylamine; bis(tetrahydrofurfurylammonium) tris(μ-oxalato)-(μ-sulfato)-di-indium(iii) dihydrate | (Hthfa)$_2$·In$_2$(SO$_4$)(C$_2$O$_4$)$_3$·2H$_2$O | monoclinic | P2$_1$/c | a=10.7581 b=12.9985 c=19.9093 β=92.876° | | | |
| bapp = N,N′-bis(3-aminopropyl)piperazine | H$_4$bapp·[In$_2$(SO$_4$)$_3$(C$_2$O$_4$)$_2$(H$_2$O)$_2$]·H$_2$O | monoclinic | I2/a | a=13.8931 b=14.6792 c=15.2418 β=111.153° | | | |
| bis(1-ethylpiperazinedi-ium) tris(μ-oxalato)-bis(sulfato)-di-indium | H$_2$epip·[In$_2$(SO$_4$)$_2$(C$_2$O$_4$)$_3$] | tetragonal | I4$_1$/a | a=26.0767 c=8.9467 | | | colourless |
| Piperazinediium bis(μ$_2$-oxalato-O,O',O'',O''')-bis(μ$_2$-sulfato-O,O')-diaqua-di-indium dihydrate | [C$_4$N$_2$H$_{12}$]$_{0.5}$InSO$_4$C$_2$O$_4$·2H$_2$O | monoclinic | P2$_1$/c | a=6.478 b=11.067 c=14.317 β=100.302° | | | |
| | Hgly·In(SO$_4$)(C$_2$O$_4$)(gly) | monoclinic | P2$_1$ | a 6.5179(2)Å b 10.9928(3)Å c 18.0301(6)Å, α 90° β 93.9700(10)° | | | |
| | CsMn(SO$_4$)(C$_2$O$_4$)$_{0.5}$·H$_2$O | monoclinic | P2$_1$/c | a = 8.065, b = 9.610, c = 9.219, β = 94.564°, Z = 4 | | | |
| | CsFe(SO$_4$)(C$_2$O$_4$)$_{0.5}$·H$_2$O | monoclinic | P2$_1$/c | a = 7.9377, b = 9.5757, c = 9.1474, β = 96.104°, Z = 4 | | | |
| | La$_2$(C$_2$O$_4$)(SO$_4$)$_2$(H$_2$O)$_3$ | monoclinic | P2$_1$/n | a=9.838 b=9.817 c=13.111 β=104.258° | | | |
| bis(μ$_3$-sulfato)-bis(μ$_2$-oxalato)-diaqua-di-lanthanum diammonium | [NH$_4$][La(H$_2$O)(SO$_4$)(C$_2$O$_4$)] | monoclinic | P2$_1$/n | a=6.629 b=8.673 c=13.867 β=93.35° | | | |
| (μ$_4$-Piperazine-diium-1,4-diacetato-O,O',O'',O''')-bis(μ$_3$-sulfato-O,O',O'')-(μ$_2$-oxalato-O,O',O'',O''')-diaqua-di-cerium(iii) dihydrate | Ce$_2$(H$_2$pda)(C$_2$O$_4$)(SO$_4$)$_2$(H$_2$O)$_2$ · 2H$_2$O | monoclinic | C2/c | a 19.353 b 6.836 c 16.400 β 94.312° | | | |
| coskrenite-(Ce) | (Ce,Nd,La)$_2$(C$_2$O$_4$)(SO$_4$)$_2$ · 12H$_2$O | triclinic | | a = 6.007(1) Å, b = 8.368(2) Å, c = 9.189(2) Å α = 99.90(2)°, β = 105.55(2)°, γ = 107.71(2)° | | 2.881 | Biaxial (-) refractive indices: n$_α$ = 1.544 n$_β$ = 1.578 n$_γ$ = 1.602; Birefringence: δ = 0.058 |
| zugshunstite-(Ce) | (Ce,Nd,La)Al(SO$_4$)$_2$(C$_2$O$_4$) · 12H$_2$O | Monoclinic | C2/c | a = 8.718 b = 18.313 c = 13.128 β = 93.90° | 2091 | 2.121 | Large REE; pink in incandescent light; blue in fluorescent light; Biaxial (+) refractive index: n$_α$ = 1.455 n$_β$ = 1.485 n$_γ$ = 1.528; |
| (μ$_4$-Piperazine-diium-1,4-diacetato-O,O',O'',O''')-bis(μ$_3$-sulfato-O,O',O'')-(μ$_2$-oxalato-O,O',O'',O''')-diaqua-di-praseodymium(iii) dihydrate | Pr$_2$(H$_2$pda)(C$_2$O$_4$)(SO$_4$)$_2$(H$_2$O)$_2$ · 2H$_2$O | monoclinic | C2/c | a 19.295 b 6.8100 c 16.377 β 94.369° | | | |
| heptakis(μ-oxalato)-bis(μ-sulfato)-tetradecaaqua-hexa-neodymium dihydrate | Nd$_6$(SO$_4$)$_2$(C$_2$O$_4$)$_7$(H$_2$O)$_{14}$·H$_2$O | triclinic | P1 | a=6.0817 b=11.8807 c=16.0749 α=73.230° β=80.873° γ=88.976° | | | |
| N,N'-dimethylethane-1,2-diaminium tetrakis(μ-sulfato)-tris(μ-oxalato)-octaaqua-tetra-neodymium | [C$_4$H$_{14}$N$_2$]·Nd$_4$(SO$_4$)$_4$(C$_2$O$_4$)$_3$(H$_2$O)$_8$ | triclinic | P1 | a=7.0649 b=11.2771 c=11.8318 α=67.370° β=80.035° γ=82.821° | | | |
| bis(μ$_3$-Sulfato-O,O,O',O'',O''')-(μ$_2$-oxalato-O,O',O'',O''')-(μ$_2$-piperazine-diium-1,4-diacetato-O,O')-diaqua-di-neodymium(iii) | Nd$_2$(H$_2$pda)(C$_2$O$_4$)(SO$_4$)$_2$(H$_2$O)$_2$] | monoclinic | C2/c | a=19.702 b=6.348 c=17.352 β=109.973° | | | |
| bis(1,4-Diazoniabicyclo[2.2.2]octane) tetrakis(μ$_2$-oxalato-O,O',O'',O''')-tetrakis(μ$_2$-sulfato-O,O',O'')-octa-aqua-tetra-neodymium(iii) dihydrate | [C$_6$N$_2$H$_{14}$][Nd$_2$(C$_2$O$_4$)$_2$(SO$_4$)$_2$(H$_2$O)$_4$]·H$_2$O | monoclinic | P2$_1$/c | a=8.523 b=28.628 c=9.306 β=96.497° | | | |
| (μ$_4$-Piperazine-diium-1,4-diacetato-O,O',O'',O''')-bis(μ$_3$-sulfato-O,O',O'')-(μ$_2$-oxalato-O,O',O'',O''')-diaqua-di-europium(iii) dihydrate | Eu$_2$(H$_2$pda)(C$_2$O$_4$)(SO$_4$)$_2$(H$_2$O)$_2$ · 2H$_2$O | monoclinic | C2/c | a=19.143 b=6.722 c=16.323 β=94.58° | | | |
| (μ$_5$-Oxalato)-(μ$_3$-sulfato)-(μ$_2$-aqua)-aqua-europium-silver | AgEu(μ$_5$-C$_2$O$_4$)(SO$_4$)(H$_2$O)$_2$ | monoclinic | P2$_1$/c | a=6.627 b=13.848 c=8.983 β=96.985° | | | |
| tetrakis(μ$_2$-oxalato)-bis(μ$_2$-sulfato)-dodeca-aqua-tetra-erbium monohydrate | Er$_4$(SO$_4$)$_2$(C$_2$O$_4$)$_4$(H$_2$O)$_{12}$·H$_2$O | monoclinic | P2$_1$/c | a=10.5598 b=12.8404 c=12.0835 β=93.327° | | | |
| bis(μ$_3$-sulfato)-bis(μ$_2$-oxalato)-diaqua-di-samarium diammonium | [NH$_4$][Sm(H$_2$O)(SO$_4$)(C$_2$O$_4$)] | monoclinic | P2$_1$/n | a=6.619 b=8.660 c=13.853 β=93.30° | | | |
| (μ$_5$-Oxalato)-(μ$_3$-sulfato)-(μ$_2$-aqua)-aqua-samarium-silver | AgSm(μ$_5$-C$_2$O$_4$)(SO$_4$)(H$_2$O)$_2$ | monoclinic | P2$_1$/c | a=6.630 b=13.829 c=9.001 β=97.128° | | | |
| | (NH$_4$)[Gd(C$_2$O$_4$)(SO$_4$)(H$_2$O)] | | | | | | large magnetocaloric effect |
| | K[Gd(C$_2$O$_4$)(SO$_4$)(H$_2$O)] | monoclinic | P2$_1$/c | a = 6.5849 b = 8.5660 c = 14.7660(2) Å, β = 112.470° Z=4 | 769.66 | 3.439 | colourless |
| potassium aquaterbium(III) oxalate sulfate | KTb(C$_2$O$_4$)(SO$_4$)(H$_2$O) | monoclinic | | a = 6.527 b = 8.507 c = 14.591 β = 112.65° Z=4 | 747.7 | | at 113K; colourless |
| (μ$_6$-Oxalato)-(μ$_4$-oxalato)-bis(μ$_3$-sulfato)-diaqua-di-silver-di-terbium | AgTb(μ$_4$-C$_2$O$_4$)$_{0.5}$(μ$_6$-C$_2$O$_4$)$_{0.5}$(SO$_4$)(H$_2$O) | monoclinic | C2/m | a=13.693 b=6.889 c=9.0885 β=116.73° | | | |
| (μ$_6$-Oxalato)-(μ$_4$-oxalato)-bis(μ$_3$-sulfato)-diaqua-di-dysprosium-di-silver | AgDy(μ$_4$-C$_2$O$_4$)$_{0.5}$(μ$_6$-C$_2$O$_4$)$_{0.5}$(SO$_4$)(H$_2$O) | monoclinic | C2/m | a=13.683 b=6.881 c=9.080 β=116.731° | | | |
| bis(1-ethyl-3-methyl-1H-imidazol-3-ium) (μ-oxalato)-bis(μ-sulfato)-tetraoxo-di-uranium monohydrate | | monoclinic | P2$_1$/c | a=11.579 b=17.312 c=13.694 β=108.178° | | | yellow |
| | (NH$_4$)$_4$[(UO$_2$)$_2$(C$_2$O$_4$)(SO$_4$)$_2$(NCS)$_2$]⋅6H$_2$O | orthorhombic | Pbam | a = 12.0177 b = 18.6182 c = 6.757 Z=2 | | | |
| Tetrapotassium bis(μ$_2$-oxalato)-tetraoxo-bis(sulfato)-di-uranium(vi) hexahydrate | K$_2$[UO$_2$(C$_2$O$_4$)SO$_4$] · 3H$_2$O | triclinic | P1 | a=5.743 b=9.544 c=11.845 α=89.49° β=84.95° γ=83.01° | | | |
| | K$_4$[(UO$_2$)$_2$C$_2$O$_4$(SO$_4$)$_2$(NCS)$_2$] | orthorhombic | Pbam | a = 11.5548 b = 7.0847 c = 13.5172 β = 93.130° Z=2 | 1104.90 | | |
| Di-rubidium dioxo-(oxalato-O,O')-(μ$_3$-sulfato)-uranium monohydrate | Rb$_2$[UO$_2$SO$_4$(C$_2$O$_4$)] · H$_2$O | orthorhombic | Pna2$_1$ | a=9.720 b=17.037 c=6.852 | | | |
| | Rb$_4$[(UO$_2$)$_2$C$_2$O$_4$(SO$_4$)$_2$(NCS)$_2$] | orthorhombic | Pbam | a = 11.5854 b = 7.3841 c = 13.9072 β = 95.754 V = Z=2 | 1183.7 | | |
| | Cs$_4$[(UO$_2$)$_2$(C$_2$O$_4$)(SO$_4$)$_2$(NCS)$_2$] · 4H$_2$O | orthorhombic | Pbam | a = 11.6539 b = 18.379 c = 6.7216 Z=2 | | | |
| Tetracesium dioxo-bis(oxalato-O,O')-(sulfato-O)-uranium(vi) hydrate | Cs$_4$[UO$_2$(C$_2$O$_4$)$_2$SO$_4$] · 2.7H$_2$O | orthorhombic | Pbca | a=9.546 b=21.119 c=21.499 | | | |