# Oxalate fluoride

An oxalate fluoride is a mixed anion compound contains both oxalate and fluoride anions. Many of these compounds have high birefringence.
With nonmetals, some are related to the oxalatophosphates and oxalatoborates with the addition of fluoride.

## Formation

For some metal oxalate complexes, fluoride can displace some oxalate. This happens with aluminium.
With gallium the reverse happens, and oxalate displaces fluoride ligands.

## Use

Difluorooxalaotoborates are under investigation as electrolytes, or electrolyte additives in lithium ion batteries or supercapacitors. Their advantage is greater thermal stability, up to 200 or 300°C, ability to form ionic liquids, and for supercapacitors, support for higher voltages (3 volts).

## List

| formula | name | crystal | space group | cell | volume | density | comment |
| N(CH$_3$)$_4$BF$_2$C$_2$O$_4$ | tetramethylammonium difluoro(oxalato)borate | | | | | | |
| N(CH$_2$CH$_3$)$_4$BF$_2$C$_2$O$_4$ | tetraethylammonium difluoro(oxalato)borate | | | | | | |
| | triethylmethylammonium difluoro(oxalato)borate | | | | | | melt 15°C; white |
| N(-CH$_2$CH$_2$CH$_2$CH$_2$-)(CH$_2$CH$_2$CH$_3$)(CH$_3$)BF$_2$C$_2$O$_4$ | N-Propyl-N-Methylpyrrolidinium Difluoro(oxalato)borate (Py$_{13}$DFOB) | | | | | | melt 3.21°C |
| N(-CH$_2$CH$_2$CH$_2$CH$_2$-)(CH$_2$CH$_2$CH$_2$CH$_3$)(CH$_3$)BF$_2$C$_2$O$_4$ | N-butyl-N-methylpyrrolidinium difluoro(oxalato)borate (Py$_1$$_4$DFOB) | | | | | | melt −5 °C |
| N(-CH$_2$CH$_2$CH$_2$CH$_2$-)(CH$_2$CH$_2$CH$_2$CH$_2$CH$_3$)(CH$_3$)BF$_2$C$_2$O$_4$ | N-pentyl-N-methylpyrrolidinium difluoro(oxalato)borate (Py$_1$$_5$DFOB) | | | | | | glass transition −74 °C |
| N(-CH$_2$CH$_2$CH$_2$CH$_2$-)(CH$_2$CH$_2$CH$_2$CH$_2$CH$_2$CH$_3$)(CH$_3$)BF$_2$C$_2$O$_4$ | N-hexyl-N-methylpyrrolidinium difluoro(oxalato)borate (Py$_1$$_6$DFOB) | | | | | | melt 31 °C |
| | 1-ethyl-1-methylpyrrolidinium difluoro(oxalato)borate | | | | | | melt 10°C; white |
| | N-ethoxyethyl-N-methylpiperidinium difluoro(oxalato)borate | | | | | | |
| | 1-ethyl-3-methylimidazolium difluoro(oxalato)borate, [C$_2$mim][DFOB] | | | | | | |
| | 1-butyl-3-methylimidazolium difluoro(oxalato)borate | | | | | | |
| | N-ethoxyethyl-N-methylpiperidinium difluoro(oxalate)borate | | | | | | ionic liquid, gl;ass transition -70 °C |
| | N-propyl-N-methylpiperidinium difluoro(oxalate)borate | | | | | | ionic liquid |
| LiBF$_2$C$_2$O$_4$ | lithium difluoro(oxalato)borate | orthorhombic | Cmcm | a = 6.2623 b = 11.437 c = 6.3002 Z = 4 | 451.22 | | |
| LiBF$_2$C$_2$O$_4$·2H$_2$O | lithium difluoro(oxalato)borate dihydrate | monoclinic | P2$_1$/c | a = 9.5580 b = 12.7162 c = 5.4387 Z = 4 | 634.63 | | |
| NaBF$_2$C$_2$O$_4$ | sodium difluoro(oxalato)borate | tetragonal | I4$_1$md | a=7.7316 c=8.5343 | 510.16 | | |
| Na(C$_2$BF$_2$O$_4$)(CH$_3$CN)$_2$ | | orthorhombic | Pnma | a=11.6932 b = 14.1254 c = 6.5130 Z=4 | 1075.76 | | B tertrahedral coordination by 2 F and twice by -OCCO- |
| Na$_2$Mn$_2$(C$_2$O$_4$)$_{2.5}$F·2H$_2$O | | triclinic | P1 | a =7.9129 b=8.8497 c=8.9252 α=74.623° β=72.361° γ=78.193° | | | birefringence 0.064@550 nm |
| Na$_3$Al(C$_2$O$_4$)$_2$F$_2$.3H$_2$O | | | | | | | soluble |
| | triethylmethylphosphonium difluoro(oxalato)borate | | | | | | melt 9°C; white |
| | diethylisobutylmethylphosphonium difluoro(oxalato)borate | | | | | | melt 23°C; white |
| | triisobutylmethylphosphonium difluoro(oxalato)borate | | | | | | |
| | tributylethylphosphonium difluoro(oxalato)borate | | | | | | |
| | lithium tetrafluoro(oxalato)phosphate (LiTFOP) | | | | | | Octahedral arrangement; P-OCCO- ring |
| | lithium difluorobis bis (oxalato) phosphate (LiDFBOP) | | | | | | Octahedral arrangement Two F trans on P; two oxalate diligands on equator |
| K$_3$Al(C$_2$O$_4$)$_2$F$_2$.3H$_2$O | | | | | | | soluble |
| [NH$_4$]$_2$VO$_2$F(C$_2$O$_4$) | | | | | | | |
| [N(CH$_3$)$_4$]$_2$VO$_2$F(C$_2$O$_4$) | | | | | | | |
| Na$_2$VO$_2$F(C$_2$O$_4$) | | | | | | | |
| K$_2$VO$_2$F(C$_2$O$_4$) | | | | | | | |
| [NH$_4$][Cr(H$_2$O)$_2$F$_2$(C$_2$O$_4$)] | | | | | | | green |
| [NH$_4$]$_3$[Cr(C$_2$O$_4$)$_2$F$_2$]·5H$_2$O | | | | | | | green |
| [NH$_4$]$_3$[Cr(C$_2$O$_4$)F$_4$]·4H$_2$O | | | | | | | |
| PyH[Cr(H$_2$O)$_2$F$_2$(C$_2$O$_4$)] Py=pyridine | | | | | | | green |
| enH$_2$[Cr(H$_2$O)$_2$F$_2$(C$_2$O$_4$)]$_2$. 2H$_2$O en=ethylenediamine | | | | | | | green |
| [Cr(en)(H$_2$O)$_2$(C$_2$O$_4$)]$_2$F. 2H$_2$O en=ethylenediamine | | | | | | | |
| [Cr(en)$_2$(C$_2$O$_4$)]$_2$F. 2H$_2$O en=ethylenediamine | | | | | | | |
| Na[Cr(H$_2$O)$_2$F$_2$(C$_2$O$_4$)]. H$_2$O | | | | | | | green |
| Na$_3$[Cr(C$_2$O$_4$)$_2$F$_2$]·5H$_2$O | | | | | | | green |
| Na$_3$[Cr(C$_2$O$_4$)F$_4$]·9H$_2$O | | | | | | | |
| K[Cr(H$_2$O)$_2$F$_2$(C$_2$O$_4$)] | | | | | | | green; 2 water and two fluorides in cis position |
| K$_3$[Cr(C$_2$O$_4$)$_2$F$_2$]·5H$_2$O | | | | | | | green |
| K$_3$[Cr(C$_2$O$_4$)F$_4$]·3H$_2$O | | | | | | | |
| [NH$_4$][MnF(C$_2$O$_4$)] | | | | | | | pale pink |
| [NH$_4$]$_2$Mn(C$_2$O$_4$)F$_3$ | | | | | | | pink; CAS 94138-08-6 |
| pyH[MnF$_2$(C$_2$O$_4$)(H$_2$O)$_2$] | | monoclinic | I2/a | a = 7.2260 b = 15.2398 c = 9.916 β = 98.22° Z = 4 | | | Octahedral coordination on Mn, Cis-F opposite oxalate. 2 aqua is trans |
| Na[MnF(C$_2$O$_4$)]·2H$_2$O | | | | | | | pale pink |
| Na$_2$Mn(C$_2$O$_4$)F$_3$ | | | | | | | pink; CAS 94138-06-4 |
| Na$_2$Mn$_2$(C$_2$O$_4$)$_{2.5}$F·2H$_2$O | | triclinic | P1 | a = 7.9129 b = 8.8497 c = 8.9252 α = 74.623$^o$ β = 72.361 $^o$ γ = 78.193 $^o$, Z = 2 | | | birefringence 0.064@550 nm; light yellow |
| K[MnF(C$_2$O$_4$)] | | | | | | | pale pink |
| K$_2$Mn(C$_2$O$_4$)F$_3$ | | | | | | | pink; CAS 4138-07-5; |
| Na$_2$Fe(C$_2$O$_4$)F$_2$ | | monoclinic | C12/c1 | a=15.8349 b=5.962 c=12.2784 β=111.968° Z=8 | 1075.0 | 2.816 | green |
| [NH$_4$]$_3$[Fe(C$_2$O$_4$)$_2$F$_2$]·H$_2$O | | | | | | | |
| [NH$_4$][Fe(C$_2$O$_4$)F$_2$]·3H$_2$O | | | | | | | |
| Na[Fe(C$_2$O$_4$)F$_2$]·2H$_2$O | | | | | | | |
| Fe(phen)$_3$(BF$_4$)(C$_2$O$_4$BF$_2$)∙H$_2$O phen = 1,10-phenanthroline | tris(1,10-phenanthroline)-iron tetrafluoroborate [ethanedioato](difluoro)borate monohydrate | orthorhombic | Pca2$_1$ | a=10.816 b=16.929 c=19.491 | | | |
| (imidH)$_2$[Fe$_2$(C$_2$O$_4$)F$_6$] | | orthorhombic | Pban | a=9.143 b=20.837 c=3.890 Z=2 | | | ladder, oxalate rungs |
| [Fe$_2$(C$_2$O$_4$)F$_4$(DMSO)$_4$] | | monoclinic | P2$_1$/n | a=7.259 b=11.409 c=13.374 β=97.26° Z=2 | | | dimer, oxalate bridged |
| Na$_3$[Fe(C$_2$O$_4$)$_2$F$_2$]·4H$_2$O | | | | | | | light green |
| KFe(C$_2$O$_4$)F | | orthorhombic | Cmc2$_1$ | a=7.7633 b=11.8767 c=10.4206 | | | red or orange |
| K[Fe(C$_2$O$_4$)F$_2$]·2H$_2$O | | | | | | | yellowish green |
| K$_2$[Fe(C$_2$O$_4$)$_2$F]·3H$_2$O | | | | | | | |
| K$_3$[Fe(C$_2$O$_4$)$_2$F$_2$]·2.8H$_2$O | | | | | | | light green |
| Co(NH$_3$)$_6$Al(C$_2$O$_4$)$_2$F$_2$.3H$_2$O | | | | | | | orange yellow; insoluble |
| [Co(NH$_3$)$_6$][Cr(C$_2$O$_4$)$_2$F$_2$]·6H$_2$O | | | | | | | pale green |
| [Co(NH$_3$)$_6$][Cr(C$_2$O$_4$)F$_4$]·4H$_2$O | | | | | | | pale green |
| [Co(NH$_3$)$_6$][Cr(H$_2$O)$_2$F$_2$(C$_2$O$_4$)]$_3$. 2H$_2$O | | | | | | | yellowish-green; sparingly soluble |
| [Co(en)$_3$][Cr(C$_2$O$_4$)$_2$F$_2$]·7H$_2$O | | | | | | | pale green |
| [Co(en)$_3$][Cr(C$_2$O$_4$)F4]·3H$_2$O | | | | | | | pale green |
| [Co(en)$_3$][Cr(H$_2$O)$_2$F$_2$(C$_2$O$_4$)]$_3$. 3H$_2$O | | | | | | | yellowish green |
| [Co(NH$_3$)$_6$][Fe(C$_2$O$_4$)F$_2$]$_3$·6H$_2$O | | | | | | | orange yellow |
| [Co(en)$_3$][Fe(C$_2$O$_4$)F$_2$]$_3$ | | | | | | | orange yellow |
| [Co(NH$_3$)$_6$]$_2$[Fe(C$_2$O$_4$)$_2$F]$_3$·9H$_2$O | | | | | | | orange yellow |
| [Co(en)$_3$]$_2$[Fe(C$_2$O$_4$)$_2$F]$_3$·4H$_2$O | | | | | | | orange yellow |
| [Co(NH$_3$)$_6$][Ga(C$_2$O$_4$)$_2$F$_2$].3H$_2$O | | | | | | | insoluble |
| Ni[Cr(H$_2$O)$_2$F$_2$(C$_2$O$_4$)]$_2$. 2H$_2$O | | | | | | | green |
| Na$_2$[GeF$_2$(C$_2$O$_4$)$_2$]·5.5H$_2$O | | | | | | | |
| K$_2$[GeF$_2$(C$_2$O$_4$)$_2$]·1.5H$_2$O | | | | | | | |
| K$_2$Ge(C$_2$O$_4$)$_2$F$_2$·2H$_2$O | | | | | | | |
| Rb$_2$VO$_2$F(C$_2$O$_4$) | | | | | | | |
| Rb$_2$Ge(C$_2$O$_4$)$_2$F$_2$·2H$_2$O | | | | | | | |
| Rb$_2$GeC$_2$O$_4$F$_4$ | | | | | | | |
| [YF(C$_2$O$_4$)(H$_2$O)$_2$]·2H$_2$O | | | | | | | |
| K$_4$Zr(C$_2$O$_4$)$_3$F$_2$·3H$_2$O | | | | | | | |
| Zr$_4$O$_3$F$_2$(C$_2$O$_4$)$_4$ · 2H$_2$O | | | | | | | |
| K$_{14}$Zr$_4$ (C$_2$O$_4$)$_5$F$_{20}$·2H$_2$O | | | | | | | |
| Na$_2$ZrC$_2$O$_4$F$_4$·2H$_2$O | | | | | | | |
| Na$_2$Zr$_2$C$_2$O$_4$F$_8$·4H$_2$O | | | | | | | |
| K$_2$ZrC$_2$O$_4$F$_4$·2H$_2$O | | | | | | | |
| KZr$_2$(OH)$_3$F$_2$(C$_2$O$_4$)$_2$ · 4H$_2$O | | | | | | | |
| KZrF$_3$C$_2$O$_4$ | | | | | | | |
| KZrF$_3$C$_2$O$_4$ · 3H$_2$O | | | | | | | |
| K$_2$ZrF$_4$C$_2$O$_4$ | | | | | | | |
| K$_2$ZrF$_4$C$_2$O$_4$ · 2H$_2$O | | | | | | | |
| K$_3$Zr(C$_2$O$_4$)$_2$F$_3$· 3H$_2$O | | | | | | | |
| K$_3$ZrF$_5$C$_2$O$_4$ | | | | | | | |
| K$_4$ZrF$_2$(C$_2$O4)$_3$ ⋅ 2H$_2$O | | | | | | | |
| K$_4$Zr(C$_2$O$_4$)$_2$CO$_3$F$_2$·5H$_2$O | | | | | | | |
| Rb$_2$ZrC$_2$O$_4$F$_4$·2H$_2$O | | | | | | | |
| Rb$_2$Zr$_2$C$_2$O$_4$F$_8$·4H$_2$O | | | | | | | |
| Rb$_3$Zr(C$_2$O$_4$)$_2$F$_3$· 3H$_2$O | | | | | | | |
| Na$_3$[NbO(C$_2$O$_4$)$_2$F$_2$]·3H$_2$O | | | | | | | |
| K$_3$[NbO(C$_2$O$_4$)$_2$F$_2$]·3H$_2$O | | | | | | | |
| K$_3$[Nb(C$_2$O$_4$)$_3$F$_2$]·5H$_2$O | | | | | | | |
| Rb$_3$[NbO(C$_2$O$_4$)$_2$F$_2$]·3H$_2$O | | | | | | | |
| Rb$_4$[Mo$_2$O$_4$ (C$_2$O$_4$)$_2$F$_2$] | | orthorhombic | | a=1065 b=8.88 c=8.09 Z=2 | | 3.52 | |
| In(C$_2$O$_4$)F. 3H$_2$O | | | | | | | |
| NH$_4$[In(C$_2$O$_4$)F$_2$].2H$_2$O | | | | | | | |
| Na[In(C$_2$O$_4$)F$_2$].2H$_2$O | | | | | | | |
| K[In(C$_2$O$_4$)F$_2$].3H$_2$O | | | | | | | |
| K$_2$[InF$_3$(C$_2$O$_4$)H$_2$O] | | monoclinic | P2$_1$/c | a=7.6943 b=9.8135 c=7.7252 β=109.648 Z=4 | 549.35 | 3.300 | |
| Rb$_2$[InF$_3$(C$_2$O$_4$)H$_2$O] | | monoclinic | P2$_1$/c | a=7.8308 b=9.9671 c=7.9327 β=111.266 Z=4 | 576.98 | 3.676 | |
| [Co(NH$_3$)$_6$][In(C$_2$O$_4$)$_2$F$_2$].2H$_2$O | | | | | | | |
| [Sn(C$_2$O$_4$)F$^-$][NH$_4$$^+$] | | monoclinic | P2$_1$/c | a = 8.2736 b = 9.6386 c = 7.7473 β = 111.229° Z = 4 | | | |
| NaSnC$_2$O$_4$F·H$_2$O | | triclinic | P1 | a = 5.9880 b = 7.2468 c = 8.2925 α = 111.020°β = 107.986° γ = 96.873° Z=2 | 308.53 | 2.871 | 0.189 @ 532 nm; colourless |
| Na$_4$Sn$_4$(C$_2$O$_4$)$_3$F$_6$ | | triclinic | P1 | a = 6.0283 b = 8.7916 c = 9.1191 α = 69.486 β = 81.508 γ = 83.017 | 446.41 | 3.514 | 0.160 @532 nm; colourless; Na 5 or 6 coordinated; Sn type 1: coordinates 2 F and 2 O's from oxalate, which bridges to another Sn type 1) Type 2 Sn has one bond to F, two bonds to Os from an oxalate, and another O from another oxalate. Sn also has weak bonds to other Sn |
| KSn(C$_2$O$_4$)F | | monoclinic | P2$_1$/c | a = 8.0692 b = 9.5398 c = 7.7245 β= 111.600° Z=4 | 552.86 | 3.181 | colourless |
| K$_2$[SnF$_2$(C$_2$O$_4$)$_2$] · 3H$_2$O | | | | | | | |
| K$_2$[SnF$_4$(C$_2$O$_4$)] · 6.5H$_2$O | | | | | | | |
| K$_2$[Sn$_2$F$_2$(C$_2$O$_4$)$_6$] · 2H$_2$O | | | | | | | |
| K$_6$[Sn$_2$F$_4$(C$_2$O$_4$)$_5$] · 2H$_2$O | | | | | | | |
| NH$_4$Sb$_2$(C$_2$O$_4$)F$_5$ | | | | | | | 0.111 @546 nm |
| (CN$_4$H$_7$)SbC$_2$O$_4$F$_2$(H$_2$O)$_{0.5}$ | | | | | | | birefringence 0.126 @546 nm |
| Na$_2$Sb$_2$(C$_2$O$_4$)F$_6$ | | | | | | | 0.188 @546 nm |
| KSb$_2$C$_2$O$_4$F$_5$ | | monoclinic | P2$_1$/c | a=5.8691 b=6.5124 c=22.178 β=91.893° Z=4 | 847.22 | 3.650 | 0.170 @532 nm |
| K$_2$Sb$_2$(C$_2$O$_4$)F$_6$ | | | | | | | 0.097 @546 nm |
| RbSb$_2$(C$_2$O$_4$)F$_5$ | | orthorhombic | P2$_1$2$_1$2$_1$ | a=5.9822 b=6.5652 c=22.7919 | 895.14 | | SHG 1.3×KDP; birefringence 0.09 @546 nm |
| [C(NH$_2$)$_3$]Sb(C$_2$O$_4$)F$_2$·H$_2$O | | | | | | | 0.323 @546 nm |
| Cs$_2$Ge(C$_2$O$_4$)$_2$F$_2$·H$_2$O | | | | | | | |
| Cs$_2$GeC$_2$O$_4$F$_4$ | | | | | | | |
| Cs$_2$VO$_2$F(C$_2$O$_4$) | | | | | | | |
| Cs$_2$ZrC$_2$O$_4$F$_4$·2H$_2$O | | | | | | | |
| Cs$_2$Zr$_2$C$_2$O$_4$F$_8$·4H$_2$O | | | | | | | |
| Cs$_4$[Mo$_2$O$_4$ (C$_2$O$_4$)$_2$F$_2$] | | orthorhombic | | a=10.72 b=9.80 c=7.95 Z=2 | | 3.98 | |
| Cs$_2$Sb$_2$(C$_2$O$_4$)$_2$F$_4$∙H$_2$O | | | | | | | birefringence 0.325@546 |
| | Lanthanum fluorooxalate ?? | | | | | | |
| | Neodymium fluorooxalate ?? | | | | | | |
| [TbrF(C$_2$O$_4$)(H$_2$O)$_2$]·2H$_2$O | | | | | | | |
| ?[DyF(C$_2$O$_4$)(H$_2$O)$_2$]·2H$_2$O | Dysprosium fluorooxalate | | C2/c | a=12.0047 b=11.0842 =8.2182 β=129.021° | | | |
| [HoF(C$_2$O$_4$)(H$_2$O)$_2$]·2H$_2$O | Holmium fluorooxalate | | | | | | |
| [ErF(C$_2$O$_4$)(H$_2$O)$_2$]·2H$_2$O | | orthorhombic | | a=11.217 b=13.046 c=9.191 Z=6 | | | |
| [TmF(C$_2$O$_4$)(H$_2$O)$_2$]·2H$_2$O | | | | | | | |
| [YBF(C$_2$O$_4$)(H$_2$O)$_2$]·2H$_2$O | | | | | | | |
| [LuF(C$_2$O$_4$)(H$_2$O)$_2$]·2H$_2$O | | | | | | | |
| K$_4$Hf(C$_2$O$_4$)$_3$F$_2$·3H$_2$O | | | | | | | |
| K$_{14}$Hf$_4$(C$_2$O$_4$)$_5$F$_{20}$·2H$_2$O | | | | | | | |
| K$_3$Hf(C$_2$O$_4$ $_2$F$_3$· 3H$_2$O | | | | | | | |
| Rb$_3$Hf(C$_2$O$_4$ $_2$F$_3$· 3H$_2$O | | | | | | | |
| K$_4$Hf(C$_2$O$_4$)$_2$CO$_3$F$_2$·5H$_2$O | | | | | | | water soluble and stable |
| H$_2$[(C$_2$O$_4$)(OH)$_3$Re·O·Re(OH)$_3$F$_2$] | | | | | | | brown |
| [NH$_4$]$_2$[(C$_2$O$_4$)(OH)$_3$Re·O·Re(OH)$_3$F$_2$] | | | | | | | brown |
| [Co(NH$_3$)$_6$]$_2$[(C$_2$O$_4$)(OH)$_3$Re·O·Re(OH)$_3$F$_2$]$_3$ | | | | | | | yellowish brown |
| [Co en$_3$]$_2$[(C$_2$O$_4$)(OH)$_3$Re·O·Re(OH)$_3$F$_2$]$_3$ | | | | | | | yellowish brown |
| K$_2$[(C$_2$O$_4$)(OH)$_3$Re·O·Re(OH)$_3$F$_2$] | | | | | | | brown |
| Ni[(C$_2$O$_4$)(OH)$_3$Re·O·Re(OH)$_3$F$_2$] | | | | | | | brown |
| Ba[(C$_2$O$_4$)(OH)$_3$Re·O·Re(OH)$_3$F$_2$] | | | | | | | brown |
| Tl$_2$[(C$_2$O$_4$)(OH)$_3$Re·O·Re(OH)$_3$F$_2$] | | | | | | | brown |
| (UF$_2$)C$_2$O$_4$ · 1$^1$/2H$_2$O | | | | | | | |
| (UF)$_2$(C$_2$O$_4$)$_3$ | | | | | | | |
| UF$_3$(H$_2$O)(C$_2$O$_4$)$_{0.5}$ | | monoclinic | C2/c | a = 17.246, b = 6.088 c = 8.589 β = 95.43° Z = 8 | | | Light green U$^{IV}$ tricapped trigonal prism coordination (9 fold); each U coordinates 6 bridging fluoride, one water, and two oxalates, which bridge to 3 other U atoms. One oxalate O is in the capped position, and the other 2 O are all on the common face. |
| (H$_4$TREN)[U$_2$F$_6$(C$_2$O$_4$)$_3$]·4H$_2$O (TREN = tris(2-aminoethyl)amine) | | monoclinic | P2$_1$/c | a = 19.1563, b = 8.9531 c = 16.6221 β = 114.633° Z = 4 | 2591.4 | 2.759 | green |
| (H$_4$APPIP)[U$_2$F$_6$(C$_2$O$_4$)$_3$]·4H$_2$O (APPIP = 1,4-bis(3-amino-propyl)piperazine) | | monoclinic | P2$_1$/c | a = 10.3309 b = 15.564 c = 17.537 β = 95.430° Z=4 | 2807.1 | 2.675 | green |
| Na$_3$[UO$_2$(C$_2$O$_4$)F$_3$]⋅4H$_2$O | | orthorhombic | Pnnm | a=7.9967 b=21.092 c=7.252 Z=4 | 1223.2 | 3.020 | yellow |
| Na$_3$[UO$_2$(C$_2$O$_4$)F$_3$]⋅6H$_2$O | | triclinic | | α°β°γ° | | | |
| K$_3$[UO$_2$(C$_2$O$_4$)F$_3$] | | triclinic | P1 | a=9.682 b=10.274 c=10.612 α=104.008° β=97.041° γ=108.774° Z=4 | 946.4 | 3.736 | yellow |
| K$_3$[UO$_2$(C$_2$O$_4$)$_2$F]⋅3H$_2$O | | triclinic | P1 | a=6.6530 b=9.105 c=12.120 α=96.372° β=90.714° γ=93.193° Z=2 | 728.4 | 2.902 | |
| Cs[UO$_2$(C$_2$O$_4$)F]⋅H$_2$O | | monoclinic | P2$_1$ | a=5.4954 b=16.226 c=9.6277 β=98.509° Z=4 | 849.0 | 4.130 | yellow |
| K$_2$[UO$_2$F$_2$(C$_2$O$_4$)] | | triclinic | P1 | a=10.981 b=11.038 c=12.629 α=108.00° β=86.79° γ=123.99° | | 1.31 | yellow |
| K$_4$[UO$_2$F$_2$(C$_2$O$_4$)$_2$] | | triclinic | P1 | a=8.768 b=8.777 c=14.857 α=101.58° β=114.27° γ=85.27° | | 4.16 | yellow |
| K$_2$[(UO$_2$)$_2$F$_4$(C$_2$O$_4$)] | | monoclinic | | a=10.792 b=12.028 c=10.615 β=136.88° | | 2.92 | yellow; oxalate is tetradentate, bridging 2 U |
| Rb$_2$[UO$_2$F$_2$(C$_2$O$_4$)] | | | | | | | yellow |
| Rb$_4$[UO$_2$F$_2$(C$_2$O$_4$)$_2$] | | | | | | | yellow |
| Rb$_2$[(UO$_2$)$_2$F$_4$(C$_2$O$_4$)] | | | | | | | yellow |