Syntheses and structures of cobalt(III) alcoholate complexes formed by addition of a water molecule across 2-pyridyl substituted imine function
作者:Sumanta Kumar Padhi、Rojalin Sahu、Vadivelu Manivannan
DOI:10.1016/j.ica.2010.11.035
日期:2011.2
Schiff bases L1-L5 N-[1-pyridine-2-ylethylidene]pyridine-2-amine (L1), 3-methyl-N-[1-pyridine-2-ylmethylidene]pyridine-2-amine (L2), 3-methyl-N-[1-pyridine-2-ylethylidene]pyridine-2-amine (L3), 4-methyl-N-[1-pyridine-2-ylmethylidene] pyridine-2-amine (L4), 4-methyl-N-[1-pyridine-2-ylethylidene]pyridine-2-amine (L5)} were synthesized and on reaction with Co(NO3)(2)center dot 6H(2)O, complexes having the molecular formulae [Co(L1O)(2)]NO3 (1), [Co(L2O)(2)]NO3 center dot xH(2)O (2a, x = 2; 2b, x = 3), [Co(L3O)(2)]NO3 (3), [Co(L4O)(2)]NO3 center dot 4H(2)O (4), [Co(L5O)(2)]NO3 (5) were isolated from the respective imines. The salt [Co(L2O)(2)]PF6 (2c) was obtained by treating 2 with KPF6. Complexes 1-5 were formed as a result of addition of a water molecule across the imine function and the resultant alcohol binds in its deprotonated form. The alcoholate ion remained bound in a facial tridentate fashion to the low-spin cobalt(III). X-ray crystal structure determination confirmed the presence of trans-trans-trans-NANPO (A = aminopyridyl and P = pyridyl) disposition in 2a and cis-cis-trans-NANPO in 2b, 2c and 4. Water dimers in 2a, 2b, 4 and water-nitrate ion network in 2a were other notable features. (C) 2010 Elsevier B.V. All rights reserved.