SYNTHESIS AND CHARACTERIZATION OF TIN(IV) AND ORGANOTIN(IV) 1,4-DIMETHYLPIPERAZINE-2,5-DIONE (CYCLOSARCOSYLSARCOSINE) ADDUCTS

The complexes [{SnCl4(L)}] 1, (SnBuCl3(L)2] 2 and [{SnR2Cl2(L)}n] (R = Me 3 or Ph 4) [L = cyclosarcosylsarcosine (1,4-dimethylpiperazine-2,5 -dione)] have been prepared and structurally characterized in the soli d state by means of Sn-119 Mossbauer spectroscopy, the determination o f lattice dynamics by temperature-dependent Sn-119 Mossbauer spectrosc opy and by vibrational studies. The structure of complex 4 has been de termined by X-ray crystallography and consists of infinite zigzag poly meric chains of trans-diphenyltin(IV) bridged by ketonic oxygen atoms. Each tin(IV) atom is surrounded by two carbons [Sn-C 2.129(7), 2.146( 8) angstrom; C-Sn-C 160.1 (3)-degrees], two chlorides [Sn-Cl 2.450(2) angstrom, Cl-Sn-Cl 98.5(1)-degrees] and two oxygen atoms [Sn-O 2.370(6 ), 2.468(6) angstrom; O-Sn-O 86.1(2)-degrees]. Tin-119 Mossbauer and v ibrational data are discussed in terms of the crystal structure and th e proposed structures. From the variable-temperature Mossbauer effect, the Debye temperatures for 1-4 were determined to be 144, 102, 128 an d 123 K respectively.