# Phosphide chloride

A Phosphide chloride is a mixed anion compound containing both phosphide (P$^{3−}$) and chloride (Cl$^−$) ions.
A common structural element is P$_7$$^{3−}$ which is called heptaphosphanortricyclane with a formal IUPAC name of heptaphosphatricyclo[2.2.1.0$^{2,6}$]heptane.
Group 12 elements, cadmium and mercury are in most of the known compounds.

## List

| formula | formula weight | crystal system | space group | unit cell Å | volume | density | comments |
| Ca$_3$PCl$_3$ | | cubic | Pm3m | a=5.713 Z=1 | 186.48 | 2.29 | |
| Cu$_6$PS$_5$Cl | 607.96 | cubic | P43m | a=9.6962 Z=4 | 911.6 | 4.430 | red |
| Sr$_2$PCl | | cubic | | a=6.18 | | | |
| Sr$_2$P$_7$Cl | | monoclinic | C2/c | a=14.571 b=12.212 c=22.292 β=103.740° Z=16 | 3853 | 3.948 | P$_7$$^{3–}$, clusters |
| Ag$_6$PS$_5$Cl | | cubic | P43m | a=10.3514 Z=4 | 1109.2 | 5.234 | orange |
| α-Cd$_3$PCl$_3$ | | hexagonal | | a=7.63 c=7.13 | | | pale yellow >530 °C or quenched |
| β-Cd$_3$PCl$_3$ | | monoclinic | | a=6.99 b=7.97 c=7.38 β=118.1° | | | pale yellow <530 °C |
| Cd$_4$P$_2$Cl$_3$ | 617.89 | cubic | Pa3 | a=12.1474 Z=8 | 1792.5 | 4.579 | yellow; band gap 2.36 eV |
| Cd$_2$P$_3$Cl | | monoclinic | C2/c | a=7.98 b=8.98 c=7.55 β= | | | brown; band gap 1.87 |
| Cd$_2$PCl$_2$ | | monoclinic | P2$_1$/n | a=7.736 b=8.957 c=7.880 β=118.92° Z=4 | 477.93 | 4.540 | yellow |
| Cd$_7$P$_4$Cl$_6$ | | cubic | Pa3 | a=11.93 | | | light green |
| Ba$_2$P$_7$Cl | | monoclinic | P2$_1$/m | a = 11.726, b = 6.829, c = 6.337, β = 95.27°, Z = 2 | | | P$_7$$^{3–}$, clusters |
| La$_3$Zn$_4$P$_6$Cl | | orthorhombic | Cmcm | a= 4.0576 b 13.632 c 21.547 Z=4 | 1191.8 | 5.013 | black; thermal conductivity 0.7 Wm$^{−1}$ K$^{−1}$ (low) |
| Eu$_2$PCl | | cubic | Fm3m | a = 6.106, Z = 2 | | | |
| W$_6$PCl$_{17}$ | | orthorhombic | Imm2 | a=6.7835 b=15.8762 c=10.0727 Z=2 | 1084.79 | 5.3168 | black |
| W$_4$(PCl)Cl$_{10}$ | | monoclinic | C2/m | a=13.257 b=9.850 c=11.400 β=91.38 Z=4 | 1488.2 | 5.161 | black; chloro-phosphinidene ligand |
| [Hg$_4$P$_2$][HfCl$_6$] | | orthorhombic | Pbca | a=12.919 b=13.263 c=16.239 Z=8 | 2783 | 5.994 | yellow |
| Hg$_2$PCl$_2$ | | monoclinic | I2/m | a=7.643,b=7.977,c=8.539,β=115.23°,Z=4 | 469.8 | 7.113 | yellow |
| Hg$_2$P$_3$Cl | | monoclinic | C2/c | a = 7.834, b = 8.844, c = 7.591, β = 98.68°, Z = 4 | | | |
| [Hg$_6$P$_4$](TiCl$_6$)Cl | | cubic | Pa3 | a=11.7675, Z=4 | 1627.2 | 6.627 | black or dark brown |
| (Hg$_6$P$_4$)(CrCl$_6$)Cl | 1627.57 | cubic | Pa3 | a=11.7364 Z=4 | 1616.6 | 6.687 | yellow; resistivity is humidity sensitive |
| (Hg$_6$P$_4$)(CuCl$_3$)$_2$ | | monoclinic | C2/c | a=23.633 b=8.956 c=14.248 β =124.213° Z=6 | 2493.9 | 6.660 | pinkish-red; ferroelectric below 37 K: 114 μC m$^{−2}$ |
| (Hg$_{23}$P$_{12}$)(ZnCl$_4$)$_6$ | | hexagonal | P62m | a=12.9774 c=11.749 Z=1 | 1713.6 | 6.035 | yellow |
| (Hg$_{11}$P$_4$)(GaCl$_4$)$_4$ | | monoclinic | C2/m | a=12.762 b=7.353 c=22.040 β=100.32 Z=2 | 2034.7 | 5.185 | yellow |
| [Hg$_4$P$_2$][ZrCl$_6$] | | orthorhombic | Pbca | a=12.899 b=13.255 c=16.196 Z=8 | 2769.1 | 5.604 | yellow |
| Hg$_4$Ag5P$_8$Cl$_5$ | | orthorhombic | Cmcm | a=11.1426 b=14.5064 c=11.8444 Z=4 | 1914.5 | 6.129 | high temp |
| Hg$_4$Ag5P$_8$Cl$_5$ | | monoclinic | C2/m | a=14.490 b=10.904 c=6.2863 β=104.094 Z=2 | 963.4 | 6.090 | |
| [Hg$_6$P$_4$Cl$_3$](SnCl$_3$) | | cubic | P2$_1$3 | a = 11.865 Z=4 | | | |
| (Hg$_6$P$_4$Cl$_3$)(PbCl$_3$) | | cubic | P2$_1$3 | a=11.8837 Z=4 | 1678.24 | 6.916 | yellow |