Assessment of density functionals and paucity of non-covalent interactions in aminoylyne complexes of molybdenum and tungsten [(η(5)-C5H5)(CO)2M≡EN(SiMe3)(R)] (E = Si, Ge, Sn, Pb): a dispersion-corrected DFT study.

Electronic, molecular structure and bonding energy analyses of the metal-aminosilylyne, -aminogermylyne, -aminostannylyne and -aminoplumbylyne complexes [(η(5)-C5H5)(CO)2M[triple bond, length as m-dash]EN(SiMe3)(Ph)] (M = Mo, W) and [(η(5)-C5H5)(CO)2Mo[triple bond, length as m-dash]GeN(SiMe3)(Mes)] have been investigated at DFT, DFT-D3 and DFT-D3(BJ) levels using BP86, PBE, PW91, RPBE, TPSS and M06-L functionals. The performance of metaGGA functionals for the geometries of aminoylyne complexes is better than GGA functionals. Significant dispersion interactions between OH, EC(O) and EH pairs appeared in the dispersion-corrected geometries.

Structure and Bonding analysis of the cationic electrophilic phosphinidene complexes of iron, ruthenium, and osmium [(η(5)-C5Me5)(CO)2M{PN(i)Pr2}]+, [(η(5)-C5H5)(CO)2M{PNR2}]+ (R = Me, (i)Pr), and [(η(5)-C5H5)(PMe3)2M{PNMe2}]+ (M = Fe, Ru, Os).

Quantum-chemical DFT calculations for the electronic, molecular structure and M-PNR(2) bonding analyses of the experimentally known cationic electrophilic phosphinidene complexes [(η(5)-C(5)Me(5))(CO)(2)M{PN(i)Pr(2)}](+) and of the model complexes [(η(5)-C(5)H(5))(CO)(2)M{PNR(2)}](+) (R = (i)Pr, Me) and [(η(5)-C(5)H(5))(PMe(3))(2)M{PNMe(2)}](+) were carried out using BP86/TZ2P/ZORA level of theory. The calculated geometrical parameters of the studied complexes are in good agreement with the reported experimental values. The short M-P bond distances and calculated Pauling bond orders (range of 1.

What is the best bonding model of the (σ-H-BR) species bound to a transition metal? Bonding analysis in complexes [(H)2Cl(PMe3)2M(σ-H-BR)] (M = Fe, Ru, Os).

Density Functional Theory calculations have been performed for the σ-hydroboryl complexes of iron, ruthenium and osmium [(H)(2)Cl(PMe(3))(2)M(σ-H-BR)] (M = Fe, Ru, Os; R = OMe, NMe(2), Ph) at the BP86/TZ2P/ZORA level of theory in order to understand the interactions between metal and HBR ligands. The calculated geometries of the complexes [(H)(2)Cl(PMe(3))(2)Ru(HBNMe(2))], [(H)(2)Cl(PMe(3))(2)Os(HBR)] (R = OMe, NMe(2)) are in excellent agreement with structurally characterized complexes [(H)(2)Cl(P(i)Pr(3))(2)Os(σ-H-BNMe(2))], [(H)(2)Cl(P(i)Pr(3))(2)Os{σ-H-BOCH(2)CH(2)OB(O(2)CH(2)CH(2))}] and [(H)(2)Cl(P(i)Pr(3))(2)Os(σ-H-BNMe(2))]. The longer calculated M-B bond distance in complex [(H)(2)Cl(PMe(3))(2)M(σ-H-BNMe(2))] are due to greater B-N π bonding and as a result, a weaker M-B π-back-bonding.

Structure and bonding analysis of dimethylgallyl complexes of iron, ruthenium, and osmium [(η5-C5H5)(CO)2M(GaMe2)] and [(η5-C5H5)(Me3P)2M(GaMe2)].

Density functional theory calculations have been performed for the dimethylgallyl complexes of iron, ruthenium, and osmium [(η(5)-C(5)H(5))(L)(2)M(GaMe(2)] (M = Fe, Ru, Os; L = CO, PMe(3)) at the DFT/BP86/TZ2P/ZORA level of theory. The calculated geometry of the iron complex [(η(5)-C(5)H(5))(CO)(2)Fe(GaMe(2))] is in excellent agreement with structurally characterized complex [(η(5)-C(5)H(5))(CO)(2)Fe(Ga(t)Bu(2))]. The Pauling bond order of the optimized structures shows that the M-Ga bonds in these complexes are nearly M-Ga single bond.

Structure and bonding energy analysis of cationic metal-ylyne complexes of molybdenum and tungsten, [(MeCN)(PMe3)4M≡EMes]+ (M = Mo, W; E = Si, Ge, Sn, Pb): a theoretical study.

The molecular and electronic structures and bonding analysis of terminal cationic metal-ylyne complexes (MeCN)(PMe(3))(4)M≡EMes](+) (M = Mo, W; E = Si, Ge, Sn, Pb) were investigated using DFT/BP86/TZ2P/ZORA level of theory. The calculated geometrical parameters for the model complexes are in good agreement with the reported experimental values. The M-E σ-bonding orbitals are slightly polarized toward E except in the complex [(MeCN)(PMe(3))(4)W(SnMes)](+), where the M-E σ-bonding orbital is slightly polarized toward the W atom.

Nature of M-Ga Bonds in cationic metal-gallylene complexes of iron, ruthenium, and osmium, [(η5-C5H5)(L)2M(GaX)]+: a theoretical study.

Density Functional Theory calculations have been performed for the cationic half-sandwich gallylene complexes of iron, ruthenium, and osmium [(η(5)-C(5)H(5))(L)(2)M(GaX)](+) (M = Fe, L = CO, PMe(3); X = Cl, Br, I, NMe(2), Mes; M = Ru, Os: L = CO, PMe(3); X = I, NMe(2), Mes) at the BP86/TZ2P/ZORA level of theory. Calculated geometric parameters for the model iron iodogallylene system [(η(5)-C(5)H(5))(Me(3)P)(2)Fe(GaI)](+) are in excellent agreement with the recently reported experimental values for [(η(5)-C(5)Me(5))(dppe)Fe(GaI)](+). The M-Ga bonds in these systems are shorter than expected for single bonds, an observation attributed not to significant M-Ga π orbital contributions, but due instead primarily to high gallium s-orbital contributions to the M-Ga bonding orbitals.

Nature of bonding in terminal borylene, alylene, and gallylene complexes of vanadium and niobium [(η(5)-C5H5)(CO)3M(ENR2)] (M = V, Nb; E = B, Al, Ga; R = CH3, SiH3, CMe3, SiMe3): a DFT study.

Density functional theory calculations have been performed for the terminal borylene, alylene, and gallylene complexes [(η(5)-C(5)H(5))(CO)(3)M(ENR(2))] (M = V, Nb; E = B, Al, Ga; R = CH(3), SiH(3), CMe(3), SiMe(3)) using the exchange correlation functional BP86. The calculated geometry parameters of vanadium borylene complex [(η(5)-C(5)H(5))(CO)(3)V{BN(SiMe(3))(2)}] are in excellent agreement with their available experimental values. The M-B bonds in the borylene complexes have partial M-B double-bond character, and the B-N bonds are nearly B═N double bonds.

Nature of M-Ga bonds in dihalogallyl complexes (η5-C5H5)(Me3P)2M(GaX2) (M = Fe, Ru, Os) and (η5-C5H5)(OC)2Fe(GaX2) (X = Cl, Br, I): a DFT study.

Density functional theory (DFT) calculations have been performed on the terminal dihalogallyl complexes of iron, ruthenium, and osmium (η(5)-C(5)H(5))(Me(3)P)(2)M(GaX(2)) (M = Fe, Ru, Os; X = Cl, Br, I) and (η(5)-C(5)H(5))(OC)(2)Fe(GaX(2)) (X = Cl, Br, I) at the BP86/TZ2P/ZORA level of theory. On the basis of analyses suggested by Pauling, the M-Ga bonds in all of the dihalogallyl complexes are shorter than M-Ga single bonds; moreover, on going from X = Cl to X = I, the optimized M-Ga bond distances are found to increase. From the perspective of covalent bonding, however, π-symmetry contributions are, in all complexes, significantly smaller than the corresponding σ-bonding contribution, representing only 4-10% of the total orbital interaction.

Structure and bonding energy analysis of M-Ga bonds in dihalogallyl complexes trans-[X(PMe3)2M(GaX2)] (M = Ni, Pd, Pt; X = Cl, Br, I).

Geometry, electronic structure, and bonding analysis of the terminal neutral dihalogallyl complexes of nickel, palladium, and platinum trans-[X(PMe(3))(2)M(GaX(2))] (M = Ni, Pd, Pt; X = Cl, Br, I) were investigated at the BP86 level of theory. The calculated geometries of platinum gallyl complexes trans-[X(PMe(3))(2)Pt(GaX(2))] (X = Br, I) are in excellent agreement with structurally characterized platinum complexes trans-[X(PCy(3))(2)M(GaX(2))]. In the gallyl complexes of nickel and palladium, the M-Ga sigma bonding orbital is slightly polarized toward the gallium atom, while in the platinum gallyl complexes, the M-Ga sigma bonding orbital is slightly polarized toward the platinum atom.

Computational studies of transition metal selectivity of octapeptide repeat region of prion protein (PrP).

We have presented a detailed theoretical (density functional theory and ONIOM) study on the structure and M-PrP (prion protein) interaction on various prion models, M(PrP) systems (where PrP = HGG, HGGGW x 3H(2)O, and PrP(61-84), and M = Zn, Cu, Ni, Co, Fe, Mn). It was shown that the geometry of the complex [Mn(HGGGW)(H(2)O)] x 2H(2)O is quite different for M = Mn(III) and Mn(II), and partial unfolding occurs only for the M = Mn(III). In [Zn{PrP(61-84)}], Zn(II) forms a bond with carbonyl oxygen of the Pro(84) residue in the axial position.