PENTACOORDINATED MOLECULES .45. MOLECULAR-STRUCTURE OF THE SPIROCYCLIC PENTACOORDINATE INDIUM(III) COMPLEX [(N-C4H9)(4)N](2)([S2C2(CN)(2)]2INCL) AND THE ISOMORPHOUS THALLIUM(III) COMPLEX [(N-C4H9)(4)N](2)([S2C2(CN)(2)]2TLBR) (REPRINTED FROM INORG CHEM, VOL 21, PG 2379, 1982)

Single-crystal X-ray diffraction analysis of the spirobis(dithia) indi um(III) chloride [(n-C4H9)(2)N](2){(S2C2(CN)(2)](2)-InCI} (2) and the isomorphous thallium(III) bromide [(n-C4H9)(4)N](2){[S2C2(CN)(2)]2TIBr } (3) shows structures that are nearly midway along the Berry coordina te connecting idealized trigonal-bipyramidal and rectangular-pyramidal geometries. They crystallize in the monoclinic space group P2(1)/c. 2 has a = 15.961 (3) Angstrom, b = 12.496 (5) Angstrom, c = 25.160 (6) Angstrom, beta = 99.59 (2)degrees, and Z = 4. 3 has a = 16.063 (5) Ang strom, b = 12.565 (8) Angstrom, c = 25.091 (7) Angstrom, beta = 100.17 (2)degrees, and 2 = 4. The final agreement factors for 2 are R = 0.05 4 and R(w) = 0.083 on the basis of 4503 reflections having I greater t han or equal to 2 theta(I); for 3 R = 0.050 and R(w) = 0.062 on the ba sis of 4027 reflections having I greater than or equal to 2 sigma(I). The structures obtained follow factors important in correlating geomet ries observed for spirocyclic phosphoranes. The atom size and electron egativity of the central atom relative to that for the halogen atom ar e of particular importance in accounting for the structural similarity of 2, 3, and the related spirocyclic spirobis(dithia) germanium fluor ide [(CH3)PPh(3)](+)[(C7H6S2)GeF](-). CH3CN (4).