PREPARATION AND CHARACTERIZATION OF DITHIOCARBAMATOCOBALT(III) COMPLEXES CONTAINING PHOSPHITES, AND MOLECULAR-STRUCTURES OF CIS-[CO((CH3)2NCS2)2(P(OCH2)3CC2H5)2]BF4 AND [CO(CH2CH2CH2CH2CH2NCS2)(P(OCH3)3)4](BF4)2

Eleven new cobalt(III)-phosphite complexes of the [CO(S-S)P4]2+- and [ Co(S-S)2P2]+-types were prepared, where S-S denotes bidentate dimethyl dithiocarbamate (dtc), diethyldithiocarbamate (etdtc), and piperidyldi thiocarbamate (pipdtc) ions, and P is 4-ethyl-2,6,7-trioxa-1-phosphabi cyclo[2.2.2]octane (etpb), trimethyl phosphite (pome), and triethyl ph osphite (poet). The [CO(S-S)2P2]+-type complexes yielded the cis-isome r in the dark, but isomerized to the trans-isomer in solution by expos ure of ultraviolet light. In the photo- and electrochemical reactions, it was inferred that the [Co(S-S)P4]2+-type complexes form a linkage- isomer in which a phosphite ligand is bound to Co(III) through the oxy gen atom. Molecular structures of cis-[Co(dtc)2(etpb)2]-BF4 (1) and [C o(pipdtc)(pome)4](BF4)2 (2) were determined by the X-ray diffraction m ethod. Crystal data: complex 1, monoclinic, C2/c, a=23.867(3), b=17.58 3(2), c=15.243(2) angstrom, beta=103.97(2)-degrees, V=6208(1) angstrom 3, Z=8, and R=0.054 for 2533 reflections; complex 2, monoclinic, P2(1) /c, a=11.259(2), b=23.865(4), c=14.293(2) angstrom, beta=93.69(1)-degr ees, V=3832.6(10) angstrom3, Z=4, and R=0.072 for 2539 reflections. Th e average Co P bond distances of 2.171(1) angstrom in 1, and of 2.208( 3) (trans to S) and 2.242(2) angstrom (trans to P) in 2 are a little s horter than those of analogous Co(III)-phosphine complexes.