Insertion reactions of small molecules into group 2 metal alkoxides; structural characterization of [Mg9(μ5−CO3)(O2COMe)8(μ3−OMe)8(MeOH)13] · MeOH · C7H8

Autor: Jawwad A. Darr, Simon R. Drake, K.M. Abdul Malik, D. Michael P. Mingos, Michael B. Hursthouse, V.-Cumaran Arunasalam, Ian Baxter
Rok vydání: 1998
Předmět:
Zdroj: Polyhedron. 17:641-657
ISSN: 0277-5387
DOI: 10.1016/s0277-5387(97)00468-3
Popis: The SO 2 inserted compounds [M(O 2 SOMe) 2 (MeOH) 2 ] ∞ (M = Mg 1; M = Ca 2) were synthesized from the reaction of the corresponding [M(OMe) 2 ] ∞ complexes in methanol, followed by recrystallization from either n -hexane or toluene. The reaction of COS or CS 2 gas with [M(OMe) 2 ] ∞ in methanol, yielded the inserted products [M({OCS}OMe) 2 (MeOH) x ] n ( x = 2, M = Mg 3, x = 3, n = 2, M = Ca 4) and [M(S 2 COMe) 2 (MeOH) x ] n ( x = 6, M = Mg 5; x = 4, M = Ca 6), respectively. The analogous reaction of [M(OMe) 2 ] ∞ (M = Mg, Ca) with CO 2 gas gave the mixed methoxide/methylcarbonato compounds [Mg(O 2 COMe(OMe)(MeOH) 1.5 ] n 7a and [Ca(O 2 COMe)(OMe)(MeOH)] n 8. Recrystallization of 7a from a “wet” hydrocarbon solvent mixture led to the crystalline product [Mg 9 (CO 3 )(O 2 COMe) 8 (OMe) 8 (MeOH) 13 ]·MeOH·C 7 H 8 7b. The corresponding insertion reaction of CO 2 gas with [M(OEt) 2 ] ∞ M = Cg, Ca) gave the mixed ethoxide/ethylcarbonato compounds [M(O 2 COEt)(OEt)(EtOH) 2 ] n (M = Mg 9; M = Ca10). Similarly, the reaction of CO 2 gas with [Mg(OR) 2 ] ∞ (R = Pr i , Bu t ) in the parent alcohol, resulted in the [Mg(O 2 COR)(OR)(ROH)] n compounds (R = Pr i 11; R = Bu t 12). All compounds have been characterized by spectroscopic techniques including NMR ( 1 H and 13 C) and IR spectroscopy, and in selected cases by TGA/DSC. Complex 7b was unambiguously characterized by single crystal X-ray diffraction. It was established that 7b is a nonameric complex comprising of two Mg 4 O 4 cubes, with a remote ninth magnesium atom held in position via two bridging methylcarbonato groups and an unusual μ 5 -carbonate ligand.
Databáze: OpenAIRE