Synthesis, X-ray diffraction analysis and nonlinear optical properties of hexacoordinated organotin compounds derived from Schiff bases

•Six new organotin derivatives of Schiff bases were prepared and characterized.•Single-crystal X-ray structure analysis of 2a, 2b and 2c confirmed formation of hexacoordinated tin complexes and a bent structure.•The second-order nonlinear optical (NLO) responses of 2a, 2b and 2c were obtained by EFISH.

The reaction of N,N-bis(2-hydroxy-4-R-benzylidene)-1,2-phenylendiimine (1 R = OH, 2 R = OMe) with R′2SnO (R′ = Me, n-Bu, Ph) provided six new organotin derivatives: dimethyl-di-n-butyl- and diphenyl[N,N′-bis(3-hydroxysalicylaldehyde)-1,2-phenylenediiminato]tin(IV) (1a), (1b), (1c) as well as dimethyl-di-n-butyl- and diphenyl[N,N′-bis(3-methoxysalicylaldehyde)-1,2-phenylenediiminato]tin(IV), (2a), (2b), (2c), respectively. All compounds were characterized by 1H, 13C and 119Sn-NMR, elemental analysis, UV, IR, and mass spectrometry. Compounds 2a, 2b and 2c were characterized by single-crystal X-ray structure analysis. In the solid state, 2a, 2b, and 2c showed the Schiff bases backbone in a bent arrangement containing a tin atom with distorted octahedral geometry, where the ligand occupies the four equatorial positions and the methyl, n-butyl, or phenyl groups occupy the trans axial positions. The second-order nonlinear optical response of representative organotin compounds 2a–c was estimated by electric field induced second harmonic (EFISH) measurements where interesting βμ values in the promising range of 10–60 × 10−30 esu were evaluated.

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