alogen Bonding Involving I-2 and d(8) Transition-Metal Pincer Complexe

Autor(es)

Freindorf, Marek ^[1] ; Yannacone, Seth ^[1] ; Oliveira, Vytor ^[2] ; Verma, Niraj ^[1] ; Kraka, Elfi ^[1]

Afiliação do(s) autor(es)

^[1] Southern Methodist Univ, Dept Chem, 3215 Daniel Ave, Dallas, TX 75275 - USA

^[2] Inst Tecnol Aeronaut ITA, Dept Quim, BR-12228900 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: CRYSTALS; v. 11, n. 4 APR 2021.
• Citações Web of Science: 4

Resumo

We systematically investigated iodine-metal and iodine-iodine bonding in van Koten's pincer complex and 19 modifications changing substituents and/or the transition metal with a PBE0-D3(BJ)/aug-cc-pVTZ/PP(M,I) model chemistry. As a novel tool for the quantitative assessment of the iodine-metal and iodine-iodine bond strength in these complexes we used the local mode analysis, originally introduced by Konkoli and Cremer, complemented with NBO and Bader's QTAIM analyses. Our study reveals the major electronic effects in the catalytic activity of the M-I-I non-classical three-center bond of the pincer complex, which is involved in the oxidative addition of molecular iodine I-2 to the metal center. According to our investigations the charge transfer from the metal to the sigma{*} antibonding orbital of the I-I bond changes the 3c-4e character of the M-I-I three-center bond, which leads to weakening of the iodine I-I bond and strengthening of the metal-iodine M-I bond, facilitating in this way the oxidative addition of I-2 to the metal. The charge transfer can be systematically modified by substitution at different places of the pincer complex and by different transition metals, changing the strength of both the M-I and the I-2 bonds. We also modeled for the original pincer complex how solvents with different polarity influence the 3c-4e character of the M-I-I bond. Our results provide new guidelines for the design of pincer complexes with specific iodine-metal bond strengths and introduce the local vibrational mode analysis as an efficient tool to assess the bond strength in complexes. (AU)

• Processo FAPESP: 18/13673-7 - Desenho de novos reagentes de iodo hipervalente com base em estudos teóricos de elevada acurácia
• Beneficiário: Vytor Pinheiro Oliveira
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado