Table 2.

Select FTIR spectral data for 1–4.

Complex	Wavenumber (cm−1)
	C=O sym	C=O asym	∆v (asym − sym)	Sn–C	Sn–O
1	1477	1735	258	559	447
2	1462	1732	270	563	455
3	1473	1735	262	559	443
4	1477	1735	258	559	447