Novel S-bridged Co(III)Pd(II) polynuclear complexes derived from [NiII{CoIII(aet)2(en)}2]Cl4 (aet=2-aminoethanethiolate).: Crystal structures of [Pd{Co(aet)2(en)}2]Cl4 and [PdCl2{Co(aet)2(en)}]Cl

The reaction of an S-bridged (CoNiCoIII)-Ni-III-Co-II trinuclear complex, [Ni{Co(aet)(2)(en)}(2)]Cl-4 (1), with Na-2[PdCl4] in a ratio of 1 : 1 gave an S-bridged (CoPdCoIII)-Pd-III-Co-II trinuclear complex, [Pd{Co(aet)(2)(en)}(2)]Cl-4 (2), while the corresponding 1 :2 reaction produced an S-bridged (CoPdII)-Pd-III dinuclear complex, [PdCl2{Co(aet)(2)(en)}]Cl (3). The crystal structures of 2 and 3 were determined by X-ray crystallography: 2 . 6B(2)O crystallizes in the monoclinic space group C2/c with a = 14.951(2), b=19.753(2), c=12.926(2) Angstrom, beta = 113.33(1)degrees, V=3505.4(9) Angstrom(3), Z=4, and R=0.034. 3 . 2H(2)O crystallizes in the monoclinic space group P2(1)/n with a= 14.282(5), b=8.497(2), c= 16.139(6) Angstrom, beta = 115.13(1)degrees, V=1773(1) Angstrom(3), Z=4, and R =0.026. In 2 the Pd-II atom is coordinated by four S atoms from two C-2-cis(S)-[Co(aet)(2)(en)](+) units, while the Pd-II atom in 3 is coordinated by two Cl atoms besides two S atoms from one octahedral C-2-cis(S)-[Co(aet)(2)(en)](+) unit. 2 was readily converted to 3 by the reaction with Na-2[PdCl4], while the conversion of 3 to 2 was achieved by reacting 3 with 1. 2 and 3 were optically resolved and their electronic absorption and CD spectral behavior is also reported.