86711-96-8Relevant articles and documents
Syntheses and crystal and molecular structures of M6(Ph2PCH2CH2CO2) 12 (M = Ni(II), Co(II))
Lewis, Gregg E.,Kraihanzel, Charles S.
, p. 2895 - 2899 (2008/10/08)
The isostructural complexes M6(Ph2PCH2CH2CO2) 12 (M = Ni(II), Co(II)) have been prepared by the interfacial reaction of solutions of Ph2PCH2CH2CO2H in CH2Cl2 and M(NO3)2 in aqueous NaHCO3. Satisfactory crystals of the Ni(II) and Co(II) complexes were obtained from CH2Cl2/C6H14 and acetone, respectively. The complexes crystallize in space group R3 with Z = 3. For M = Ni(II): a = b = 27.559 (5) ?, c = 21.607 (4) ?, V = 14212 (8) ?3, p(calcd) = 1.205 g cm-3 with mol wt 3439.3. For M = Co(II): a = b = 27.597 (4) ?, c = 21.425 (4) ?, V = 14131 (7) ?3, p(calcd) = 1.213 g cm-3 with mol wt 3440.6. The common structure is based on a M6O6 ring with a nearly octahedral field of five oxygen atoms and one phosphorus atom about each M. Half of the Ph2PCH2CH2CO2- is coordinated through the carboxylato oxygens to two M sites (average M-O = 2.04 ± 0.03 ?) in a conventional syn-syn manner, with the phosphorus donor site remaining uncoordinated. The other Ph2PCH2CH2CO2- ligands chelate the metal sites through P and O2 with M-O2 = 2.128 (3) and 2.169 (5) ? for Ni(II) and Co(II), respectively. The carboxylato oxygen O2 also bridges to a second metal site with M′-O2 = 2.069 (3) and 2.116 (5) ? for Ni(II) and Co(II), respectively. The second carboxylato oxygen atom (O1) bridges to still a third metal atom (M-O1 = 2.034 (3) and 2.037 (5) ? for Ni(II) and Co(II), respectively) to complete a η3 bonding scheme. The M-M distances of 3.510 (1) ? for Ni(II) and 3.557 (1) ? for Co(II) preclude any type of direct metal-metal bonding.
