Thallides are compounds containing anions composed of thallium. Thallium may occur as a monatomic ion ( in LiMg2Tl), as a cluster of several atoms (such as ), or as a polyatomic structure in thallides. They are a subclass of trielides, which also includes gallides and indides. A more general classification is polar intermetallics, as clusters contain delocalized multicentre bonds. Thallides were discovered by Eduard Zintl in 1932.

Mixed anion compounds with thallides include halides (bromides and chlorides), oxides, and tetrelates (silicate, germanate).

Production

Thallide compounds can be produced by melting metals together in a tantalum crucible under an inert argon atmosphere. However if arsenic is included in the mix, it can react with the crucible wall.

A low temperature production route, is to dissolve an alkali metal in liquid ammonia, and use that to reduce a thallium salt, like thallium iodide.

Properties Thallide compounds are dense, dense to X-rays and usually metallic grey or black in appearance.

Thallide clusters mostly do not follow Wade-Mingos rules or the Zintl–Klemm concept, as they have too small a negative charge. They can be called "hypoelectronic".

Reactions In liquid ammonia, oxidation occurs yielding metal amides, and thallium metal.

Thallides react with water and air.

List formulasystemspace groupunit cellvolumedensitycommentrefLiTlcubicPmma=3.43melts at 508 °CLi2TlorthorhombicCmcma=4.741 b=10.023 c=4.786decomposes at 381 °CLi5Tl2Rma=4.716 c=20.399melts at 448 °CLi3TlcubicFm3ma=6.67melts at 447 °CLi22Tl5 (Li4Tl)cubicF3ma=20.003NaTlcubicFdm3D diamond structure mesh for Tl; melts at 305 °CNaTltetragonalI41/amda=5.2341 c=7.5290 Z=4206.26grey;Na2TlorthorhombicC2221a=13.9350 b=8.8797 c=11.6927[Tl4]8– tetrahedra; melts at 154 °CNaTl2decomposes at 154 °CNa6TlcubicF3ma=24.154melts at 77.4KTlorthorhombicCmcaa=15.239 b=15.069 c=8.137[Tl6]6– Compressed octahedra; melts incongruently at 268 °CK5Tl8melts at 273 °CK10Tl7monoclinicP21/ca = 10.132 b = 22.323 c = 13.376 β = 93.14° Z=4[Tl7]7– pentagonal bipyramid K10Tl6O2[Tl6]6–K8Tl11rhombohedralRca=9.991 c=5.084[Tl11]7– pentacapped trigonal prism; melts at 320 °CK49Tl108Pm3a = 17.28.7 Z=1K5Tl17orthorhombicCccmK6Tl17orthorhombicCccma = 16.625 b = 23.594 c = 15.369 Z = 860288.173@22 °C; metallic; ρ270 = 22.6 μΩ·cm, α = 0.0023 K−1K10Tl6O2orthorhombicCmcma=8.3755 b=32.102 c=8.8634 Z=42383.14.597dark greyNa7KTl4orthorhombicPbama=16.2860 c=11.2771 Z=82991.14.519[Tr4]8−Na9K16Tl~25[Et4N]2[{Tl(Fe(CO)4)2}2][(PPh2)2N]2[Tl2Fe6(CO)24]monoclinicP21/ca=17.120 b=50.71 c=16.785 β=116.90°[Et4N]4[Tl4Fe8(CO)30][Et4N]6[Tl6Fe10(CO)36]K8ZnTl10band gap 0.17 eVK8GaTl10tetragonalP4/nnca=10.1858 c=13.6371 Z=21414.95.695K49Ga2Tl108Rb8Tl11[Tl11]7– pentacapped trigonal prism Rb15Tl27P2mRb17Tl41hexagonalFdma = 10.3248 c = 17.558Rb10Tl6O2orthorhombicCmcma=8.7176 b=33.2934 = 9.12422648.195.300dark grey; [Tl6]6–Na7RbTl4orthorhombicPbama=16.3584 b=16.3581 c=11.3345 Z=83033.04.660@123K [Tl4]8− tetrahedraK4Rb4Tl11Cl0.1rhombohedralRca=10.0948 c=51.027 Z=64503.36.087Rb8GaTl10tetragonalP4/nnca=10.4714 c=14.0007 Z=21535.26.051Rb49Ga2Tl108Sr3Tl5orthorhombicCmcma = 10.604 b = 8.675 c = 10.985 Z = 41010.58.445silvery, brittle; [Tl5]6– square pyramidal clustersYMgTlhexagonalP62ma=7.505 c=4.5985 Z=37.05metallic; black powderPd3TltetragonalI4/mmma=4.10659 c=15.3028 Z = 4258.07PalladothalliteSrPdTl2orthorhombicCmcma = 4.486 b = 10.991 c = 8.154 Z = 4Na13(Cd~0.70Tl~0.30)27cubicIma ≃ 15.92 Z = 4Tl from 0.24 to 0.33K14Cd9Tl21hexagonalP2ma = 9.884 c =17.173 Z = 2Na9K16Tl18Cd3hexagonalP63/mmca = 11.136 c = 29.352 Z=2Rb5Cd2Tl11orthorhombicAmm2a = 5.5999 b = 17.603 c = 12.896 Z = 2Na12K18In53Tl7R3ma=16.846 c=43.339 Z=4Na6TlSb4monoclinicC2/c15.154 b = 10.401 c = 17.413 β = 113.57° Z = 8metallicK6Tl2Sb3monoclinicC2/ca = 9.951 b = 17.137 c = 19.640 β = 104.26° Z = 8CsTlorthorhombicFddd[Tl6]6–Cs3.45K3.55Tl7tetragonalI41/aa = 13.6177 c = 25.5573 Z = 84739.35.681[Tl7]7−Cs7.29K5.71Tl13monoclinicC2/ca = 30.7792 b = 11.000 c = 14.0291 β = 112.676° Z = 44382.75.835[Tl7]7− and [Tl6]6–K3.826Cs4.174Tl11Cs8Tl11[Tl11]7– pentacapped trigonal prismCs15Tl27hexagonalP2mCs4Tl2OtrigonalRma = 11.986 c = 20.370 Z = 92534.35.640silvery black; stable to 523 °C; decomposes in airCs18Tl8O6Cs10Tl6SiO4monoclinicP21/ca=18.9121 b=11.4386 c=14.8081 β=90.029°[Tl6]6–Cs10Tl6GeO4monoclinicP21/ca=19.034 b=11.4883 c=14.8633 β=90.033°[Tl6]6–Cs10Tl6SnO3orthorhombicPnmaa=14.8908Å b=19.052 c=11.5855[Tl6]6–Rb14CsTl27hexagonalCs8GaTl10tetragonalP4/nnca=10.777 c=14.354 Z=21667.36.328Cs5Cd2Tl11orthorhombicAmm2a = 5.6107 b = 18.090 c = 13.203 Z = 2Cs8Tl11Pd0.84rhombohedralRca = 10.6l0 c = 54.683 Z = 6Cs8Tl11Cl0.8rhombohedralRca=10.4691 c=53.297 Z = 65058.86.578Cs8Tl11Br0.9rhombohedralRca=10.5608 c=53.401 Z = 65157.96.539Cs5Rb3Tl11Cl0.5rhombohedralRca=10.3791 c=52.437 Z = 64892.06.502Cs5.7K2.3Tl11Cl0.6rhombohedralRca=10.3291 c=51.909 Z = 64796.36.469BaTl2hexagonalP63/mmcBaTl4 monoclinicC2/ma = 12.408 b = 5.351 c = 10.383 β = 116.00° Z = 4519.6silveryLaMgTlhexagonalP62ma=7.813 c=4.7784 Z=37.25metallic; black powderCeMgTlhexagonalP62ma=7.741 c=4.7375 Z=37.47metallic; black powderPrMgTlhexagonalP62ma=7.702 c=4.7150 Z=3242.97.60metallic; black powderNdMgTlhexagonalP62ma=7.666 c=4.6945 Z=3242.97.74metallic; black powderSmMgTlhexagonalP62ma=7.603 c=4.6593 Z=38.10metallic; black powderEuTl2EuPdTl2orthorhombicCmcma=4.466 b=10.767 c=8.120 Z=4390511.35silvery metallicGdMgTlhexagonalP62ma=7.556 c=4.6312 Z=3229.97.74metallic; black powderTbMgTlhexagonalP62ma=7.518 c=4.6088 Z=3226.78.52metallic; black powderDyMgTlhexagonalP62ma=7.495 c=4.5932 Z=3224.18.69metallic; black powderHoMgTlhexagonalP62ma=7.471 c=4.5835 Z=3metallic; black powderErMgTlhexagonalP62ma=7.449 c=4.5715 Z=3metallic; black powderTmMgTlhexagonalP62ma=7.432 c=4.5541 Z=3metallic; black powderLuMgTlhexagonalP62ma=7.402 c=4.5400 Z=3metallic; black powderK5TaAs4Tl2orthorhombicPnmaRb5TaAs4Tl2orthorhombicPnmaa = 19.196 b = 11.104 c = 7.894 Z = 4spiro at TaSrPtTl2orthorhombicCmcma = 4.491 b = 10.990 c = 8.140 Z = 4Na12K38Tl48Au2Tl7 and Tl9 cluster + aurideK3Au5TlorthorhombicImmaa = 5.595 b =19.706 c =8.430 Z = 4Rb2Au3TlorthorhombicPmmaa = 5.660 b = 6.741 c = 9.045 Z = 4BaAuTl3tetragonalI4/mmma = 4.8604 c = 12.180 Z = 2Ba2AuTl7orthorhombicPmmaa=21.919 b=5.193 c=10.447BaAu0.40Tl1.60orthorhombicImmaa = 5.140 b = 8.317 c = 8.809 Z = 4BaHg0.80Tl3.20monoclinicC2/ma=12.230 b=5.234 c=10.379 β = 115.272600.310.523silvery

References