title: The strongest CO binding and the highest C-O stretching frequency.
abstract: A coupled-cluster study is performed on CO bound BeY complexes (Y = O, CO3, SO4, NH, NCN, and NBO) to understand the effect of attached ligands (Y) on the CO binding ability and C-O stretching frequency (νCO). Herein, we report that BeNCN has the highest CO binding ability (via both C- and O-side binding) among the studied neutral Be-based clusters, whereas OCBeSO4has the highest νCOamong the neutral carbonyls. The nature and extent of shift in νCOcompared to free CO are explained in terms of change in polarization in the bonding orbitals of CO and relative contribution from OC→BeY or CO→BeY σ-donation, and OC←BeY or CO←BeY π-back-donation. The largest blue-shift in OCBeSO4and the largest red-shift in COBeNH are consequences of the smallest OC←BeSO4π-back-donation and the largest CO←BeNH π-back-donation, respectively.
authors.affiliation: Department of Chemistry and Centre for Theoretical Studies, Indian Institute of Technology Kharagpur, Kharagpur - 721302, India. pkc@chem.iitkgp.ernet.in.
authors.forename: Ranajit
authors.initials: R
authors.lastname: Saha
authors.affiliation: Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados, Unidad Mérida, Km 6 Antigua Carretera a Progreso. Apdo. Postal 73, Cordemex, 97310, Mérida, Yuc., Mexico. sudip.pan@cinvestav.mx gmerino@cinvestav.mx.
authors.forename: Sudip
authors.identifier: http://orcid.org/0000-0003-3172-926X
authors.initials: S
authors.lastname: Pan
authors.affiliation: Fachbereich Chemie, Philipps-Universität Marburg Hans-Meerwein-Straße, 35032 Marburg, Germany. frenking@chemie.uni-marburg.de.
authors.forename: Gernot
authors.initials: G
authors.lastname: Frenking
authors.affiliation: Department of Chemistry and Centre for Theoretical Studies, Indian Institute of Technology Kharagpur, Kharagpur - 721302, India. pkc@chem.iitkgp.ernet.in.
authors.forename: Pratim K
authors.initials: PK
authors.lastname: Chattaraj
authors.affiliation: Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados, Unidad Mérida, Km 6 Antigua Carretera a Progreso. Apdo. Postal 73, Cordemex, 97310, Mérida, Yuc., Mexico. sudip.pan@cinvestav.mx gmerino@cinvestav.mx.
authors.forename: Gabriel
authors.identifier: http://orcid.org/0000-0002-2507-4052
authors.initials: G
authors.lastname: Merino