Dichloro(phthalocyaninato)cobalt(III), PcCoCl2, and potassium thiocyanate react in ethanol with reduction of the macrocycle and ligand exchange to give potassium bis(isothiocyanato)(phthalocyaninato)cobalt(III)-ethanol, K[PcCo(CNS)2]-C2H5OH (1). *H NMR data of 1 in acetone suggest three isomers with respect to the nature of the metal-thiocyanate bond. Monomeric 1 decomposes in the presence of water to form (phthalocyaninato) (µ-thiocyanato)cobalt(III), [PcCoSCN], (2). 2 is also obtained by treating PcCoCCl3COO-CCl3COOH with KSCN in ethanol or by reacting PcCoCl2 with KSCN in boiling water. Infrared as well as X-ray powder diffraction data give evidence for the bridged structure of 2, which exhibits a dc dark conductivity of ctrt = 6 X 10'3 S/cm without external doping. [PcCoSCN]" (2) is almost insoluble in noncoordinating solvents; N-donor bases such as pyridine (py) and pyrazine (pyz) decompose the bridged structure to give PcCo(py)SCN-CHCl3 (3) and PcCo(pyz)SCN (4), respectively. By X-ray analysis 3 was found to be a thiocyanate complex in the solid state. PcCo(py)SCN-CHCl3 (3) crystallizes in the monoclinic space group P2¡/n with a = 19.381 (1) Á, b = 18.316 (9) Á, c = 10.115 (6) X, ß = 90.79 (5)°, and Z = 4.NMR measurements of 3 in CDC13 give evidence for the existence of both S-and N-bonded isomers in solution. IR data of PcCo(pyz)SCN (4) compared to those of PcCo(py)SCN-CHCl3 (3) indicate a metal-S bond in PcCo(pyz)SCN (4). In contrast to the case for (phthalocyaninato)cobalt, (tetrabenzoporphyrinato)cobalt(III) forms exclusively monomeric isothiocyanate complexes TBA[(TBP)Co(NCS)2] ( 6) and (TBP)CoNCS ( 7).
AbstractThe preparation of tetrabenzoporphyrinatocobalt(II) and tetrabenzoporphyrinatocobalt(III)- cyanide derivatives either with terminal or bridging cyanide is described. The IR and the 1H NMR spectra as well as magnetic measurements are in accordance with the proposed structures and the oxidation states of the complexes. μ-Cyano(tetrabenzoporphyrinato)cobalt(III) (4) exhibits a powder conductivity of σRT = 4 ·10-2 S/cm, without additional external doping.
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