Crystal structures of 5,12-dimethyl-1,4,8,11-tetraazacyclotetradecane cobalt(III) mono-phenylacetylide and bis-phenylacetylide

Abstract

Reported in this contribution are the synthesis and crystal structures of new mono- and bis-phenylacetylides based on Co III (DMC) (DMC is 5,12-dimethyl-1,4,8,11-tetraazacyclotetradecane). Chlorido(5,12-dimethyl-1,4,8,11-tetraazacyclotetradecane)(phenylethynyl)cobalt(III) chloride-acetonitrile-methanol (1/1/1), [Co(C8 H5)Cl(C12 H28 N4)]Cl·CH3 CN·CH3 OH, 1, and (5,12-dimethyl-1,4,8,11-tetraazacyclotetradecane)bis(phenylethynyl)cobalt(III) trifluoromethanesulfonate-dichloromethane (2/1), [Co(C8 H5)2 (C12 H28 N4)]2 (CF3 SO3)2 ·CH2 Cl 2, 2, were prepared under weak-base conditions in satisfactory yields. Single-crystal X-ray diffraction studies revealed that both 1 and 2 adopt a pseudo-octahedral symmetry in which the Cl - Co - C angles of 1 and C - Co - C of 2 range from 177.7(2) to 178.0(2)° and from 177.67(9) to 179.67(9)°, respectively. In both structures, the Co III metal center is coordinated in the equatorial plane by four N atoms, in which the N - Co - N angles range from 85.6(3) to 94.4(3)°. The structure of 1 features two crystallographically independent molecules in its triclinic cell (Z′ = 2), which are related to each other by pseudo-monoclinic symmetry. The crystal investigated was twinned by a symmetry operator of the approximate double-volume C-centered cell (180° rotation around [201] of the actual triclinic cell), with a refined twin ratio of 0.798(3) to 0.202(3). Both methanol solvent molecules in 1 are disordered, the major occupancy rates refined to 0.643(16) and 0.357(16). Compound 2 also contains two molecules in the asymmetric unit, together with two trifluoromethanesulfonate anions [of which one is disordered; occupancy values of 0.503(16) and 0.497(16)] and a disordered dichloromethane [occupancy values of 0.545(12) and 0.455(12)].