Experimental and quantum-chemical characterization of heavy carbon subchalcogenides: Infrared detection of SeC$_3$Se

Abstract

High-resolution infrared studies of laser ablation products from carbon-selenium targets have revealed a new vibrational band at 2057 cm −1 that is identified as the ν 3 vibrational fundamental of the SeC 3 Se cluster. Because of the rich isotopic composition of selenium and the heavy nuclear masses involved, the vibrational band shows a relatively compact and complex structure despite the simple linear geometric arrangement. Overall, rotationalvibrational lines of six isotopologues could be assigned and fitted permitting the derivation of an accurate selenium-carbon bond length. Spectroscopic analysis has been greatly supported by high-level quantumchemical calculations of the molecular structure and the harmonic and anharmonic force fields performed at the CCSD(T) level of theory. Scalarrelativistic effects on the molecular structure were also considered but found of little importance.