| The solid state chemistry of group 13 has provided prolific structural diversity of cluster compounds. The isoelectronic relation between the elements of the group and a mixture of the elements from the adjacent groups was used in a search for new phases at the Zintl border. Two new compounds, Na 49Cd58.34(3)Sn37.69(2) and Na13Cd 20.1(1)E6.9 (E = Sn, Pb), contain exo-bonded clusters and more specifically the trade mark for group 13, icosahedra . Other ternary compounds have been also synthesized: the first Hg-containing clathrate-I type structure, Rb8Hg4Sn42, and the related to the Laves phases AHg2-xPbx (A = K, Rb).;Two cadmium compounds have been synthesized with one and the same stoichiometry, A0.4Cd2 (A = Na, K), but with very different structures. Another class of binary compounds of group 12 that were studied was a series of alkali-metal amalgams. The compounds A3Hg20 (A = Rb, Cs) form new type structure closely related to clathrate-I K3Hg 11 is the first example of an amalgam in the alpha-La3Al 11 class and expands both the cation size and VEC ranges previously known for it. Together with A5Hg19 (A = Rb, Cs) it is built on defect polyhedra originating from the 18-vertex unit of BaAl 4; one of the compounds A7Hg31 (A = Y, Rb) had been previously reported with a different cell choice. A second-order phase transition has been suggested a possible result for the difference.;The conventional view that Zintl ions of the type T4-9 for the elements of group 14 (tetrels, T) could be obtained only via reactive solution of intermetallic phases into molecular solvents has been disproved. The compounds A4T9 and A12T 17, both of which contain the nine atom naked clusters, have been made in solids by high temperature routes. They have been shown to exist for all tetrel elements (except carbon) with variety of alkali-metal countercations.;The substitution of a vertex in T4-9 with an atom of electron poorer element (group 12 and 11) provided new ternary series: A6T8E, A6Pb8Au 2. Despite their equal electron count and stoichiometry they form different tetrahedra based units: dimers (T4)Hg(T4) in Cs 6T8Hg (T = Sn,Pb), oligomers [(Pb4)Cd(Pb 4)Cd(Pb4)Cd]10- or chains 1infinity [(Pb4)Au]4- in A6Pb 8Au2 (A = K, Cs). |
