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

An intramolecular donor/acceptor SnN bonding connection in a set of triphenyl- and diphenyl-(halogeno)tin(IV) C,N-chelates, Ph2XSnL, where Ph=C6H5, X=Ph, Cl or Br and L1=2-(dimethylaminomethyl)phenyl-, C6H4(CH2NMe2)-2, and L2=2,6-bis[(dimethylaminomethyl)phenyl]-, C6H3(CH2NMe2)2-2,6, respectively, was studied by 119Sn, 15N, 13C and 1H NMR spectroscopy in solution of non-coordinating solvent (CDCl3) and by 119Sn 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 δ(119Sn) and δ(15N) and values of J(119Sn, 13C) and J(119Sn, 15N) coupling constants. The set was extended by compound [2,6-C6H3(CH2NMe2)2]PhSnCl2 (5a), that is the decomposition product of compound [2,6-C6H3(CH2NMe2)2]Ph2SnCl (5). This 5a was characterized by NMR spectroscopy and its structure was estimated by X-ray diffraction techniques.