Synthesis and crystal structures of heterobimetallic 2-(diphenylphosphino)-pyridine complexes containing an Fe→M (M = CuI, AgI or HgII) donor–acceptor bond and a mononuclear iron(II) complex bearing a pair of planar strained four-membered chelate rings
Abstract
Four heterobimetallic Fe–M (M = CuI, AgI or HgII) complexes and a mononuclear iron(II) complex containing a pair of strained planar four-membered chelate rings have been synthesized via the reaction of a neutral organometallic trans-Fe(CO)3(dppy)2 L [dppy = 2-(diphenylphosphino)pyridine] with the corresponding metal perchlorates. Their structures have been determined by single-crystal X-ray analysis. In [CuL(Me2CO)]ClO4·1.75Me2CO 1, [CuL(H2O)]ClO4·CH2Cl22, [AgL(dppy)]ClO4·0.5MeOH 3, [HgL(H2O)(OClO3)]ClO4· 2.5H2O·0.5MeOH 4 and cis-[Fe(CO)2(dppy-P,N)2][ClO4]2·CH2Cl25, the Fe–M (M = Cu, Cu, Ag or Hg) distances are 2.501(2), 2.512(2), 2.760(1) and 2.545(1)Å, respectively, unequivocally indicating the existence of a dative Fe→M bond. To our knowledge, 3 is the first binuclear iron(0)–silver(I) donor–acceptor complex to be fully characterized by single-crystal X-ray analysis, and 5 provides the first example of a first-row transition-metal complex which incorporates two planar four-membered chelate rings involving P and N donor atoms.