Theoretical investigations on thallium halides: Relativistic and electron correlation effects in T1X and T1X3 compounds (XF, C1, Br, and I)

✍ Scribed by Peter Schwerdtfeger; Josef Ischtwan

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 977 KB
• Volume: 14
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.540140806

✦ Synopsis

Relativistic and electron correlation effects in thallium halides TlXand TlX3 (X=F, C1, Br, and I) are investigated by extensive ab initio configuration interaction calculations. Spin-orbit coupling is included at the Hartree-Fock level for the diatomic TlBr and T1I. At the best level of treatment of electron correlation (quadratic configuration interaction), the calculated molecular properties are in good agreement with experimental results, i.e., for the diatomic thallium halides deviations from experimental values are <0.06 A for bond distances, <0.14 mdyn/W for force constants, <35 kJ/mol for dissociation energies, and <0.3 D for dipole moments. The convergence of the Mgller-Plesset series up to the fourth order is discussed. Two alternative structures of TIIR are compared. At the Mgller-Plesset level of theory, the trigonal planar structure with thallium in the oxidation state + 3 is the preferred gas phase arrangement compared with the bent arrangement containing a linear I:, unit and thallium in the oxidation state + 1, the difference being ca. 95 kJ/mol. Vibrational frequencies are predicted for all trigonal planar thallium(II1) halides.