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Tris(pyrazol-1-yl)borate and tris(pyrazol-1-yl)methane: A DFT study of their different binding capability toward Ag(I) and Cu(I) cations
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Inorganica Chimica Acta
Volume 362, Issue 12, 15 September 2009, Pages 4358-4364
Tris(pyrazol-1-yl)borate and tris(pyrazol-1-yl)methane: A DFT study of their different binding capability toward Ag(I) and Cu(I) cations (Article)
Casarin, M.acd , Forrer, D.ad, Garau, F.a, Pandolfo, L.ad, Pettinari, C.b, Vittadini, A.cd
a Dipartimento di Scienze Chimiche, Università degli Studi di Padova, Via Marzolo 1, 35131 Padova, Italy
b Dipartimento di Scienze Chimiche, Camerino, Italy
c Istituto di Scienze Molecolari, CNR, Padova, Italy
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Abstract
Density functional theory has been used to study the electronic structure of [M(tp)] and [M(tpm)]+ conformers (M = Cu, Ag; tp = tris(pyrazol-1-yl)borate anion, tpm = tris(pyrazol-1-yl)methane) and the energetics of their interconversions. Results for the free tp ligand are similar to those of tpm [M. Casarin, D. Forrer, F. Garau, L. Pandolfo, C. Pettinari, A. Vittadini, J. Phys. Chem. A 112 (2008) 6723], indicating an intrinsic instability of the tripodal conformation (κ3-like). This points out that, though frequently observed, the κ3-coordinative mode is unlikely to be directly achieved through the interaction of M(I) with the κ3-like tp/tpm conformer. Analogously to the [M(tpm)]+ molecular ions, the energy barrier for the κ2-[M(tp)] → κ3-[M(tp)] conversion is computed to be negligible. Though κn-[M(tp)] and κn-[M(tpm)]+ (n = 1, 2, 3) have similar metal-ligand covalent interactions, the negative charge associated to the tp ligand makes the M-tp bonding stronger
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Tris(pyrazol-1-yl)borate and Tris(pyrazol-1-yl)methane: A DFT Study of Their Different Binding Capability Toward Ag(I) and Cu(I) Cations
No full textDensity functional theory has been used to study the electronic structure of [M(tp)] and [M(tpm)]+ conformers (M = Cu, Ag; tp = tris(pyrazol-1-yl)borate anion, tpm = tris(pyrazol-1-yl)methane) and the energetics of their interconversions. Results for the free tp ligand are similar to those of tpm [M. Casarin, D. Forrer, F. Garau, L. Pandolfo, C. Pettinari, A. Vittadini, J. Phys. Chem. A 112 (2008) 6723], indicating an intrinsic instability of the tripodal conformation (k3-like). This points out that, though frequently observed, the k3-coordinative mode is unlikely to be directly achieved through the interaction of M(I) with the k3-like tp/tpm conformer. Analogously to the [M(tpm)]+ molecular ions, the energy barrier for the k2-[M(tp)] → k3-[M(tp)] conversion is computed to be negligible. Though kn-[M(tp)] and kn-[M(tpm)]+ (n = 1, 2, 3) have similar metal–ligand covalent interactions, the negative charge associated to the tp ligand makes the M-tp bonding stronger
Density functional theory study of the binding capability of tris(pyrazol-1-yl)methane toward Cu(I) and Ag(I) cations
No full textDensity functional theory (DFT) has been used to look into the electronic structure of [M(tpm)]+ molecular
ion conformers (M ) Cu, Ag; tpm ) tris(pyrazol-1-yl)methane) and to study the energetics of their
interconversion. Theoretical data pertaining to the free tpm state the intrinsic instability of its κ3-like
conformation, thus indicating that, even though frequently observed, the κ3-tripodal coordinative mode is
unlikely to be directly achieved through the interaction of M(I) with the κ3-like tpm conformer. It is also
found that the energy barrier for the κ2-[M(tpm)]+ f κ3-[M(tpm)]+ conversion is negligible. As far as the
bonding scheme is concerned, the tpm f M(I) donation, both σ and π in character, is the main source of the
M(I)-tpm bonding, whereas back-donation from completely occupied M(I) d orbitals into tpm-based π*
levels plays a negligible role
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