Isolation and structural characterization of trans-beta-{(C-meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane)(diaquo)}nickel(II) perchlorate and cis-alpha-{(C-racemic-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane)(diisothiocyanato)}nickel(II)

[[abstract]]The beta-[Ni(C-meso-1,7-CTH)](ClO4)(2) (1,7-CTH = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) isomer having trans-III (RRSS) conformation leads to the formation of trans-beta-[Ni(C-meso-1,7-CTH)(H2O)(2)](ClO4)(2) in 1:1 (v/v) H2O-MeOH mixture containing 1 M NaCl and exists as the equilibrium mixture of low spin square planar beta-[Ni(C-meso-1,7-CTH)](Cl)(2) and high spin octahedral trans-beta-[Ni(C-meso-1,7-CTH)(H2O)(2)](ClO4)(2) complexes. alpha-[Ni(C-rac-1,7-CTH)](ClO4)(2) possesses trans-V (RRRR) conformation and forms cis-alpha-[Ni(C-rac-1,7-CTH)(NCS)(2)] with NaSCN in MeOH. The structures of trans-beta-[Ni(C-meso-1,7-CTH)(H2O)(2)](ClO4)(2) and cis-alpha-[Ni(C-rac-1,7-CTH)(NCS)(2)] complexes have been characterized by X-ray diffraction studies. The aquo complex exhibits three characteristic bands at approximately 688, 445 and 290 nm. cis-alpha-[Ni(C-rac-1,7-CTH)(NCS)(2)] shows a band corresponding to d-d transitions at approximately 583 nm.[[fileno]]2010337010173[[department]]化學