Syntheses, Reactivity, and Molecular Structure of RSRS-[Ni(tmc)SC6H5](PF6), RRSS-[Ni(tmc)SC6H5](CF3SO3), and RRSS-[Ni(tmc)](CF3SO3) (tmc = 1,4,8,11-Tetramethyl-1,4,8,11-tetraazacyclotetradecane)

Article abstract of DOI:10.1021/ic00127a029

The RSRS and RRSS isomers of [Ni(tmc)](OTf)2 (tmc = 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane; OTf(1-) = CF3SO3(1-)) react with NaSC6H5 to yield the corresponding high spin, five-coordinate derivatives,[Ni(tmc)SC6H5](OTf). The molecular structure of each has been determined by X-ray diffraction. RRSS-[Ni(tmc)SC6H5](OTf) crystallized in the monoclinic space group P21/n, with a = 12.648(3) ?, b = 15.145(4) ?, c = 14.765(4) ?, β = 113.96(2)°, V = 2584(1) ?**3,and Z = 4. The coordination sphere about Ni is best described as squarepyramidal with a Ni-S bond distance of 2.369(2) ? and Ni-Nav of 2.128 ?. RSRS-[Ni(tmc)SC6H5](PF6) crystallized in the monoclinic space group P21/n, with a = 13.037(5) ?, b = 15.407(7) ?, c = 13.706(7) ?, β = 113.53(3)°, V = 2524(2) ?**3, and Z = 4. The Ni resides in a highly distorted square pyramid with a shorter Ni-S distance, 2.352(2) ? and correspondingly longer Ni-Nav distance of 2.149 ?. Alternatively [Ni(tmc)SR](OTf) may be produced by oxidative addition of disulfide, R2S2 (R = C6H5, C2H5), to Ni(tmc)(OTf). The second-order rate constant, k1, for reaction with (C6H5)2S2 is 120 M**-1 s**-1.(C2H5)2S2 reacts 5 orders of magnitude more slowly consistent with its greater S-S bond dissociation energy. The nickel thiolates react with haloalkanes, RX (RX = CH3I, C2H5I, (CH3)2CHI, C6H5CH2Cl), producing [Ni(tmc)X](OTf) and C6H5SR. The reaction is second order with k2 decreasing inthe order, CH3I > C2H5I > (CH3)2CHI. Strikingly, for reactions with a given RX, the RRSS isomer reacted ca. 350 times faster than the RSRS isomer. RRSS-[Ni(tmc)](OTf).Na(OTf) has also been characterized, having crystallized in the monoclinic space group C2/c, with a = 24.690(13) ?, b = 11.261(5) ?, c = 9.681(6) ?, β = 91.03(4)°, V = 2691(2) ?**3, and Z = 4. The macrocycle provides the Ni(I) ion with a square planar coordination environment in which there are two distinctNi-N bond distances, 2.120(5) and 2.095(5) ?.