The infrared spectra of tin(IV) tetrahalides and dialkyltin dihalides in the 500-50 cm−1 region

Multinuclear 1D and 2D NMR Investigations on the Interaction between the Pyrimidic Nucleotides 5′-CMP, 5′-dCMP, and 5′-UMP and Diethyltin Dichloride in Aqueous Medium

“…The 35 Cl solution NMR data of the supernatant shed some further, albeit indirect light on this proposal. It is well-known that the 35 Cl NMR signal of the chloride anion is very sharp and displays a chemical shift around δ ϭ 0.…”

“…[34] The Raman spectrum displays two characteristic bands at 434 and 568 cm -1 that were tentatively assigned to the ν(Sn-O-P) and ν(Sn-O-Sn) vibration frequencies, respectively. [35][36][37] On the basis of all previous data, four tin-phosphate complexes ( Figure 4) are conceivable for the solid-state structure obtained from mixing 5'-CMP and Et 2 SnCl 2 . Unexpectedly, elemental analysis data from samples of the complex depend on the acid (HCl or HBr) used for the adjustment of the pH of the supernatant from which this solid precipitates; nevertheless, these data are self-consistent and reproducible (Table 6).…”

“…It is well-known that the 35 Cl NMR signal of the chloride anion is very sharp and displays a chemical shift around δ ϭ 0. [40] In contrast, covalently bound chlorine generally fails to provide a useful 35 Cl signal since it is smeared out in the noise. The supernatant of the solid with proposed structure 8 falls into the latter category.…”

“…Provided that 8 has identical structures in the supernatant and the solid, this structure implies that one chloride ion has been split off from the initial Et 2 SnCl 2 , while the second is covalently bound. The absence of any visible 35 Cl resonance in a solution of 8 implies the presence of covalently bound chlorine (as indicated by elemental analysis), necessarily being in fast exchange with the ionic chloride which must also be present.…”

“…The differences in 31 P chemical shift titration profiles are used as indicators for an interaction between diethyltin dichloride and the mononucleotides. Subsequently, the structural features of the interaction are characterised by 1D and 2D NMR correlation techniques involving 1 H, 13 C, 15 N, 31 P and 119 Sn nuclei, completed by 35 Cl NMR data where appropriate. Proton detected 1 H-119 Sn HMQC [13][14][15] and phosphorus detected 31 P-1 H HOESY [16,17] have been reported to be very efficient for the characterisation of organotin complexes in solution.…”