The Nature of Nonclassical Chalcogeno-Carbonyl Ligands

María L.G. Sansores-Paredes; Michelle P. van Dongen; Celine Nieuwland; Pascal Vermeeren; F. Matthias Bickelhaupt; Célia Fonseca Guerra

doi:10.1021/acs.inorgchem.5c05165

The Nature of Nonclassical Chalcogeno-Carbonyl Ligands

María L.G. Sansores-Paredes
, Michelle P. van Dongen
, Celine Nieuwland
, Pascal Vermeeren
, F. Matthias Bickelhaupt
, Célia Fonseca Guerra

Chemical Sciences

Research output: Contribution to journal › Article › peer-review

Abstract

Coordination of chalcogeno-carbonyl ligands CX (X = O, S, Se) to transition metals can induce either expansion (classical) or contraction (nonclassical) of the C–X bond. While nonclassical CO complexes have been extensively studied, the heavier analogs CS and CSe remain comparatively underexplored, despite their higher π-acidity and potential for broader applications. In this work, we used Kohn–Sham molecular orbital theory together with canonical energy decomposition analysis to investigate the nature and bonding characteristics of [M(CO)₅(CX)]^q complexes (M^q = Ti^2–, V^–, Cr⁰, Mn⁺, Fe²⁺). Our results show that nonclassical behavior occurs in the cationic metal complexes, where the trend set by the electrostatic [M]–CX interactions (favoring C–X contraction) dominates the trend set by [M]–CX π-backdonation (favoring C–X expansion), even for the heavier chalcogeno-carbonyl ligands, despite their higher π acidity.

Original language	English
Pages (from-to)	1551-1560
Number of pages	10
Journal	Inorganic Chemistry
Volume	65
Issue number	2
DOIs	https://doi.org/10.1021/acs.inorgchem.5c05165
Publication status	Published - 19 Jan 2026

ASJC Scopus subject areas

Physical and Theoretical Chemistry
Inorganic Chemistry

Access to Document

10.1021/acs.inorgchem.5c05165

Cite this

@article{843860da879b4565ba850b14991aa01a,

title = "The Nature of Nonclassical Chalcogeno-Carbonyl Ligands",

abstract = "Coordination of chalcogeno-carbonyl ligands CX (X = O, S, Se) to transition metals can induce either expansion (classical) or contraction (nonclassical) of the C–X bond. While nonclassical CO complexes have been extensively studied, the heavier analogs CS and CSe remain comparatively underexplored, despite their higher π-acidity and potential for broader applications. In this work, we used Kohn–Sham molecular orbital theory together with canonical energy decomposition analysis to investigate the nature and bonding characteristics of [M(CO)5(CX)]q complexes (Mq = Ti2–, V–, Cr0, Mn+, Fe2+). Our results show that nonclassical behavior occurs in the cationic metal complexes, where the trend set by the electrostatic [M]–CX interactions (favoring C–X contraction) dominates the trend set by [M]–CX π-backdonation (favoring C–X expansion), even for the heavier chalcogeno-carbonyl ligands, despite their higher π acidity.",

author = "Sansores-Paredes, \{Mar{\'i}a L.G.\} and \{van Dongen\}, \{Michelle P.\} and Celine Nieuwland and Pascal Vermeeren and Bickelhaupt, \{F. Matthias\} and \{Fonseca Guerra\}, C{\'e}lia",

note = "Publisher Copyright: {\textcopyright} 2026 American Chemical Society",

year = "2026",

month = jan,

day = "19",

doi = "10.1021/acs.inorgchem.5c05165",

language = "English",

volume = "65",

pages = "1551--1560",

journal = "Inorganic Chemistry",

issn = "0020-1669",

publisher = "American Chemical Society",

number = "2",

}

TY - JOUR

T1 - The Nature of Nonclassical Chalcogeno-Carbonyl Ligands

AU - Sansores-Paredes, María L.G.

AU - van Dongen, Michelle P.

AU - Nieuwland, Celine

AU - Vermeeren, Pascal

AU - Bickelhaupt, F. Matthias

AU - Fonseca Guerra, Célia

PY - 2026/1/19

Y1 - 2026/1/19

N2 - Coordination of chalcogeno-carbonyl ligands CX (X = O, S, Se) to transition metals can induce either expansion (classical) or contraction (nonclassical) of the C–X bond. While nonclassical CO complexes have been extensively studied, the heavier analogs CS and CSe remain comparatively underexplored, despite their higher π-acidity and potential for broader applications. In this work, we used Kohn–Sham molecular orbital theory together with canonical energy decomposition analysis to investigate the nature and bonding characteristics of [M(CO)5(CX)]q complexes (Mq = Ti2–, V–, Cr0, Mn+, Fe2+). Our results show that nonclassical behavior occurs in the cationic metal complexes, where the trend set by the electrostatic [M]–CX interactions (favoring C–X contraction) dominates the trend set by [M]–CX π-backdonation (favoring C–X expansion), even for the heavier chalcogeno-carbonyl ligands, despite their higher π acidity.

AB - Coordination of chalcogeno-carbonyl ligands CX (X = O, S, Se) to transition metals can induce either expansion (classical) or contraction (nonclassical) of the C–X bond. While nonclassical CO complexes have been extensively studied, the heavier analogs CS and CSe remain comparatively underexplored, despite their higher π-acidity and potential for broader applications. In this work, we used Kohn–Sham molecular orbital theory together with canonical energy decomposition analysis to investigate the nature and bonding characteristics of [M(CO)5(CX)]q complexes (Mq = Ti2–, V–, Cr0, Mn+, Fe2+). Our results show that nonclassical behavior occurs in the cationic metal complexes, where the trend set by the electrostatic [M]–CX interactions (favoring C–X contraction) dominates the trend set by [M]–CX π-backdonation (favoring C–X expansion), even for the heavier chalcogeno-carbonyl ligands, despite their higher π acidity.

UR - https://www.scopus.com/pages/publications/105027636726

U2 - 10.1021/acs.inorgchem.5c05165

DO - 10.1021/acs.inorgchem.5c05165

M3 - Article

AN - SCOPUS:105027636726

SN - 0020-1669

VL - 65

SP - 1551

EP - 1560

JO - Inorganic Chemistry

JF - Inorganic Chemistry

IS - 2

ER -

The Nature of Nonclassical Chalcogeno-Carbonyl Ligands

Abstract

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this