PREPARATIONS, PROPERTIES, AND CRYSTAL-STRUCTURES OF TRANS-[RH(CN)2(NH3)4]CL-H2O AND TRANS-[RH(CN)2(EN)2]CL

Syntheses of the title new complex compounds of Rh(III) were successful. Single, sharp IR peaks of nu(C = N) were observed at 2130 cm-1 (trans-[Rh(CH)2(NH3)4]Cl.H2O) and 2170 cm-1 (trans-[Rh(CN)2(en)2]Cl), respectively. The values of the ligand field tetragonal parameter D(t) were estimated to be -366 and -377 cm-1, respectively, based on the 1E(g)a (D4h<--1A1g transition (37100 cm-1: trans-[Rh(CN)2(NH3)4]+;37000 cm-1: trans-[Rh(CN)2(en)2]+). The X-ray crystal data are: for trans-[Rh(CN)2(NH3)4]Cl.H2O, orthorhombic, Cmcm, a=7.961(3), b=17.295(2), c=7.436(3) angstrom, D(c)=1.79, D(m)=1.79 g cm-3, Z=4; for trans-[Rh(CN)2(en)2]Cl, monoclinic, P2(1)/n, a=9.665(4), b=9.107(3), c=6.779(3) angstrom, beta=109.68(2)degrees, D(c)=1.85, D(m)=1.83 g cm-3, Z=2. The N=C-Rh-C=N sequence of trans-[Rh(CN)2(NH3)4]+ lies in a line of m2m symmetry in the crystal. The central Rh atom of trans-[Rh(CN)2(en)2]+ occupies the special position of inversion symmetry. The important geometrical data of the complexes are Rh-N=2.07(1), Rh-C=2.02(3) A, N-Rh-N=88.0(5)degrees (trans-[Rh(CN)2(NH3)4]+) and Rh-N=2.080(3), 2.072(3), Rh-C=2.047(4) angstrom, N-Rh-N (within chelate ring)=82.7(1)degrees (trans-[Rh(CN)2(en)2]+).