Solution and cross-polarization/magic angle spinning NMR investigation of intramolecular coordination Sn-N in some organotin(IV) C,N-chelates

摘要

An intramolecular donor/acceptor Sn-N bonding connection in a set of triphenyl-and diphenyl-(halogeno)tin(IV) C,N-chelates, Ph_2XSnL, where Ph=C_6C_5, X=Ph, Cl or Br and L~1=2-(dimethylaminomethyl)phyenyl-, C_6H_4(CH_2NMe_2)-2, and L~2=2,6-bis-[(dimethylaminomethyl)phenyl]-,C_6H_3(CH_2NMe_2)_2-2,6, respectively, was studied by ~(119)Sn, ~(15)N, ~(13)C and ~1H NMR spectroscopy in solution of non-coordinating solvent (CDCl_3) and by ~(119)Sn cross-polarization/magic angle spinning NMR techniques in the solid-state. The existence of Sn-N coordination bonds was confirmed in studied compounds and their strengths were evaluated through the values of NMR spectra parameters of nuclei directly involved in Sn-N connection, namely by characteristic changes of chemical shifts ##delta#(~(119)Sn) and #delta#(~(15)N) and values of J(~(119)Sn, ~(13)C) and J(~(119)Sn, ~(15)N) coupling constants. The set was extended by compound [2,6-C_6H_3(CH_2NMe_2)_2]PhSnCl_2 (5a), that is the decomposition product of compound [2,6-C_6H_3(CH_2NMe_2)_2]Ph_2SnCl (5). This 5a was characterized by NMR spectroscopy and its structure was estimated by X-ray diffraction techniques.