Ultra-violet absorption spectra of SnBr and SnI

Abstract

The B²Σ–X²II system of SnBr has been photographed in absorption following the flash photolysis of SnBr₄. A vibrational analysis allows the determination of T_e, ω′_e and ω′_ex′_e(in addition to ω″_e and ω″_ex″_e, which are already known ¹⁰). The frequencies of the band heads can be expressed as ν= 33062.4 + 304.3 (ν′+ 1/2)– 0.7₁(ν′+ 1/2)²– 246.7(ν″+ 1/2)+ 0.6₄(ν″+ 1/2) cm^–1.

A similar system of bands has been observed in the flash photolysis of SnI₄. The frequencies of the band heads are given by ν= 32172.8 + 241.1(ν′+ 1/2)– 0.1₇(ν′+ 1/2)²– 199.0(ν″+ 1/2)+ 0.5₅(ν″+1/2)² cm^–1.

Consideration of the parameters of this expression shows that the bands are probably due to the B²Σ–X²II transition of SnI, for which no spectrum has been previously reported.