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 triphe nyl- and diphenyl-(halogeno)tin(IV) C,N-chelates. Ph2XSnL, where Ph = C6H5, X = Ph, Cl or Br and L' = 2-(dimethylaminomethyl)phenyl-, C6H,(CH,NMe,)-2. and L' = 2,6-bis[(dimethylaminomethyl)phenyll-, C H ',(CH,NMe1)2-2,6, resp ectively, was studied by "'Sn, 'N, "C and 'H NMR spectroscopy in solution o f non-coordinating solvent (CDCI,) and by "'Sn cross-polarization ' imagic angle spinning NMR techniques in the solid-state. The existence of Sn-N coo rdination 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 s hifts 6('"'Sn) and 5(`N) and values of J('"Sn. '3Q and J("'Sn, 'N) coupling constants. The set was extended by compound [2,6-C1H3(CH,NMe,),jPhSnCl, (5 a), that is the decomposition product of compound [2,6-C,H3(CH,NMe,),]Ph,Sn Cl (5), This 5a was characterized by NMR spectroscopy and its structure was estimated by X-ray diffraction techniques. O 2001 Elsevier Science B.V. Al l rights reserved.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 L-1 = 2-(dimethylaminomethyl)phenyl -, C6H4(CH2NMe2)-2, and L-2 = 2,6-bis[(dimethylaminomethyl)phenyl]-, C6H3(C H2NMe2)(2)-2,6, respectively, was studied by Sn-119, N-15, C-13 and H-1 NMR spectroscopy in solution of non-coordinating solvent (CDCl3,) and by Sn-11 9 cross-polarization/magic angle spinning NMR techniques in the solid-state . The existence of Sn-N coordination bonds was confirmed in studied compoun ds and their strengths were evaluated through the values of NMR spectra par ameters of nuclei directly involved in Sn-N connection, namely by character istic changes of chemical shifts delta(Sn-119) and delta(N-15) and values o f J(Sn-119, C-13 and J(Sn-119, C-13) coupling constants. The set was extend ed by compound [2,6-C6H3(CH2NMe2)(2)]PhSnCl2 (5a), that is the decompositio n product of compound [2,6-C6H3(CH2NMe2)(2)]Ph2SnCl (5), This 5a was charac terized by NMR spectroscopy and its structure was estimated by X-ray diffra ction techniques. (C) 2001 Elsevier Science B.V. All rights reserved.