Halogenostannates of Glycine and Its Derivatives

Abstract Five new halogenostannates of amino acids glycine (Gly), sarcosine (Sar), dimethylglycine (DMG), and betaine (Bet) were synthesized and characterized by structural analysis, infrared and Raman spectroscopy, diffuse reflectance spectroscopy, and photoluminescence. The compounds (GlyH)2SnBr6·2H2O (I), (SarH···SarH)SnBr6 (II), (DMGH)2SnBr6·2H2O (III), and (BetH···BetH)SnBr6 (IV) contain SnBr62– hexabromostannate anion with Sn(IV), whereas (SarH)2SnCl4 (V) has SnCl42– tetrachlorostannate anion with Sn(II). In the structures of (SarH···SarH)SnBr6 and (BetH···BeH)SnBr6, amino acid cations form centrosymmetric (A+···A+) dimers through the O–H···O hydrogen bond. The bandgaps of I–IV estimated from the diffuse reflectance spectra have close values. The hexabromostannates show similar broad green emission near 511 nm under 250 nm excitation and violet-blue emission near 428 nm under 370 nm excitation.