Ligand properties of N-heterocyclic and Bertrand carbenes: A density functional study

Lai, Chun Liang; Guo, Wen Hsin; Lee, Ming‐Tsung; Hu, Ching Han

doi:10.1016/j.jorganchem.2005.07.058

Cited by 31 publications

(14 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The calculated Δ N values for complexes R 2 E–Ni(CO) 3 lie in the range from 0.006 for A-Ge-Ni to 0.173 for C-Ge-Ni (Table S9, Chart ). The value 0.122 for Ard-C corresponds well with the previous calculations. , As it could be expected, the weakest donors are A -type tetrylenes, bearing electron-withdrawing substituents. The strongest donors are tetrylenes stabilized by intramolecular coordination, C and A + C .…”

Section: Resultssupporting

confidence: 91%

“…The value 0.122 for Ard-C corresponds well with the previous calculations. 131,143 As it could be expected, the weakest donors are A-type tetrylenes, bearing electron-withdrawing substituents. The strongest donors are tetrylenes stabilized by intramolecular coordination, C and A + C. In these cases, charge transfer is larger than that for Arduengo's carbene Ard-C, known as one of the strongest neutral electron donors.…”

Section: ■ Computational Approachesmentioning

confidence: 85%

See 1 more Smart Citation

Tetrylenes: Electronic Structure, Stability, Reactivity, and Ligand Properties—A Comparative DFT Study

Nechaev

2021

Organometallics

View full text Add to dashboard Cite

A comprehensive theoretical analysis of the electronic structure, reactivity, and ligand properties for various types of divalent derivatives of group 14 elements, tetrylenes, R 2 E (E = C, Si, Ge, Sn), was performed at the DFT level. For a deeper understanding of the stability and the origin of chemical properties of tetrylenes, molecules stable in the monomeric form in the solid state with real substituents were considered. Tetrylenes stabilized by various factors were studied: steric shielding, attachment of electron-withdrawing substituents to E atom, electron delocalization, and intramolecular coordination bonding. The effect of various stabilization factors on the chemical and ligand properties of tetrylenes was investigated using theoretical modeling. The obtained data can be used for the rational design of tetrylenes and their complexes with transition metals and can also serve as a comprehensive tutorial on the theoretical aspects of the structure and reactivity of tetrylenes within one approach and at one level of theory.

show abstract

Section: Resultssupporting

confidence: 91%

Section: ■ Computational Approachesmentioning

confidence: 85%

Tetrylenes: Electronic Structure, Stability, Reactivity, and Ligand Properties—A Comparative DFT Study

Nechaev

2021

Organometallics

View full text Add to dashboard Cite

show abstract

“…We found values for 1 and 2 to be in good agreement with previous theoretical estimations. 82,85 Charge transfer increases from 0.162 to 0.228 in the order 1a < 2a < 3a < 5a < 4a < 6a, following a parallel trend to the increasing softness of 1-6. Indeed, the influence of h on DN is more pronounced than that of c since the relative decrease of c upon changing from 1 to 6 is only 13% (30% decrease for h).…”

Section: Nhc Donor Properties: Charge Transfer In [Rhcl(nhc)(co) 2 ]mentioning

confidence: 94%

N-heterocyclic carbenes bearing two, one and no nitrogen atoms at the ylidene carbon: insight from theoretical calculations

2009

View full text Add to dashboard Cite

Electronic structure, thermodynamic stability and ligand properties in LRh(CO)2Cl complexes of a series of N-heterocyclic carbenes (NHCs) were studied at the DFT level. The systems under study are: imidazolin-2-ylidene (1), imidazolidin-2-ylidene (2), cyclic(alkyl)(amino)carbene (CAAC, 3), pyrazolin-3-ylidene (4), pyridin-2-ylidene (5), and pyridin-4-ylidene (6). The main structural feature influencing the properties of these species is the number of nitrogen atoms at the ylidene carbon. A decrease of the number of nitrogen atoms on the one hand leads to an increase in donor ability and ligand-to-metal bond strength, but lowers the stability of the NHC on the other hand. The number of nitrogen atoms can be taken as a key parameter for the classification of carbenes into 2N-NHC, 1N-NHC and r-NHC (r = remote).

show abstract

“…As mentioned above, experimental and computational studies have sought to compare the electronic properties of carbenes to a variety of ligands by determination of carbonyl stretching frequencies in transition metal complexes. 14-17,30,36,38,40,43, 53 We have previously used LKB descriptors to predict the Tolman electronic parameter (TEP) 35,47,48 for P-donor ligands. 1, 3 The limited availability of data for carbene ligands covered by this work (7-10 ligands) 38,40 prevents the derivation of predictive linear regression models.…”

Section: Analysis (1) Individual Descriptorsmentioning

confidence: 99%

A ligand knowledge base for carbenes (LKB-C): maps of ligand space

et al. 2009

View full text Add to dashboard Cite

We describe the development of a ligand knowledge base designed to capture the properties of C-donor ligands coordinating to transition metal centres, LKB-C. This knowledge base has been developed to describe both singlet (Arduengo and Fischer) and triplet (Schrock) carbenes, as well as related neutral monodentate C-donor ligands. The descriptors evaluated and used have been derived from a range of coordination environments to maximise their transferability and hence utility for the investigation of such ligands. These descriptors have been analysed with different statistical approaches, both individually to determine their chemical context, and collectively by principal component analysis thereby allowing the derivation of maps of ligand space for different ligand sets. The utility of such maps for investigating ligand similarity and identification of target areas for future ligand designs has been discussed. In addition, linear regression models have been fitted for the prediction of a calculated response variable, highlighting further potential applications of such a knowledge base.

show abstract

Ligand properties of N-heterocyclic and Bertrand carbenes: A density functional study

Cited by 31 publications

References 55 publications

Tetrylenes: Electronic Structure, Stability, Reactivity, and Ligand Properties—A Comparative DFT Study

Tetrylenes: Electronic Structure, Stability, Reactivity, and Ligand Properties—A Comparative DFT Study

N-heterocyclic carbenes bearing two, one and no nitrogen atoms at the ylidene carbon: insight from theoretical calculations

A ligand knowledge base for carbenes (LKB-C): maps of ligand space

Contact Info

Product

Resources

About