Synthesis, Crystal Growth and Characterization of Iodo- and Bromobismuthates of Sarcosine with Sarcosinium···Sarcosinium Dimeric Cation

In the present paper, we report on the synthesis and determination of the crystal structures of two halogenobismuthate salts of sarcosine: (SarH)3(Bi2I9) (I) and (SarH)2(BiBr5) (II). The salt (I) crystallizes in the centrosymmetric space group P21/c and the salt (II) in the polar space group Pna21. Sarcosinium···sarcosinium dimeric cations, present in both compounds, were observed for the first time. IR and Raman spectra were registered and discussed on the basis of their structures. Bandgaps were determined by powder diffuse reflectance measurements. The polar symmetry of (II) has been confirmed by the pyroelectric studies.