Structure, spectra and chemical properties of ditoluenetitanium

Tairova, Gulshen G.; Krasochka, O. N.; Ponomaryov, Vasily I.; Kvashina, E. F.; Shvetsov, Yury A.; Lisetsky, Evgeny M.; Kiryukhin, D. P.; Atovmyan, L. O.; Borod'ko, Yury G.

doi:10.1007/bf01035841

Cited by 29 publications

(16 citation statements)

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“…The C−C bond lengthening versus that in benzene decreases in the order Hf > Zr > Ti and W > Mo > Cr, thus indicating greatest back-donation for the heavy atoms. Similar C−C bond lengths (1.415 Å) have been reported in the X-ray structures of Ti(C 6 H 5 Me) 2 , Cr(C 6 H 6 ) 2 , and other metal(0) bis(arene) complexes …”

Section: Resultssupporting

confidence: 79%

Metal−Ligand Bonding and Bonding Energetics in Zerovalent Lanthanide, Group 3, Group 4, and Group 6 Bis(arene) Sandwich Complexes. A Combined Solution Thermochemical and ab Initio Quantum Chemical Investigation

et al. 1996

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In this paper we report a comparative experimental thermochemical and ab initio quantum chemical study of metal−ligand bonding and bonding energetics in the group 3, lanthanide, group 4, and group 5 zerovalent bis(arene) sandwich complexes Sc(TTB)2 (1) Y(TTB)2 (2), Gd(TTB)2 (3), Dy(TTB)2 (4), Ho(TTB)2 (5), Er(TTB)2 (6), Lu(TTB)2 (7), Ti(TTB)2 (8), Zr(TTB)2 (9), Hf(TTB)2 (10), Ti(toluene)2 (11), and Nb(mesitylene)2 (12) (TTB = η6-(1,3,5-tBu)3C6H3). Derived D̄(M−arene) values by iodinolytic batch titration calorimetry in toluene for the process M(arene)2(solution) → M° + 2arene(solution) are rather large (kcal/mol): 45(3) (1), 72(2) (2), 68(2) (3), 47(2) (4), 56(2) (5), 57(2) (6), 62(2) (7), 49(1) (8), 55(2) (11), 64(3) (9), 67(4) (10), and 73(3) (12). Ab initio relativistic core potential calculations on M(C6H6)2, M = Ti, Zr, Hf, Cr, Mo, W, reveal that the metal−ligand bonding is dominated by strong (greater in group 4 than in the group 6 congeners) δ back-bonding from filled metal d x y and d x 2 -y 2 orbitals to unoccupied arene π orbitals, which decreases in the order Hf > Zr > Ti > W > Mo > Cr. Calculated geometries and D̄(M−C6H6) values (at the MP2 level) yield parameters in favorable agreement with experiment. The latter analyses evidence a great sensitivity to electron correlation effects. Marked, group-centered dependences of the measured D̄(M−arene) values on the sublimation enthalpies of the corresponding bulk metals, on the metal atomic volumes, and, for the lanthanides and Y, on the corresponding free atom f → d promotion energies are also evident.

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Section: Resultssupporting

confidence: 79%

Metal−Ligand Bonding and Bonding Energetics in Zerovalent Lanthanide, Group 3, Group 4, and Group 6 Bis(arene) Sandwich Complexes. A Combined Solution Thermochemical and ab Initio Quantum Chemical Investigation

et al. 1996

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“…The syn conformations found for the crystals of (2) and (3) have previously been observed for the monosubstituted bis-arene complexes of other transition metals, viz. (Tairova et al, 1982), Mo (Miao, 1982), W (Prout et al, 1982), Nb (Clark et al, 1996)] and ( 6 -C 6 H 5 COOH) 2 Cr (Braga et al, 2001), while compounds ( 6 -C 6 H 5 R) 2 Cr [R = CF 3 (Larson et al, 1987) or NMe 2 (Lynch et al, 1990)] have an antiperiplanar conformation in the crystals. The C atoms of the aromatic rings in (2)-(4) are close to being eclipsed.…”

Section: Resultsmentioning

confidence: 99%

Substituent effects in bis(arene)chromium compounds containing a CN group in the aromatic ring

Khrustalev

Vasil’kov

Antipin

2005

Acta Crystallogr Sect B

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The crystal structures of Cr(PhCN)(2) (2), (PhCN)Cr(PhCH(3)) (3) and (PhCN)Cr(PhCF(3)) (4) prepared by means of the Metal Vapor Synthesis (MVS) technique have been determined. Compounds (2), (3) and (4) crystallize as discrete sandwich complexes having intrinsic C(2v)(mm2), C(s)(m) and C(1)(1) symmetries, respectively. The X-ray diffraction study has revealed a synperiplanar conformation for (2) and (3), and a synclinal conformation for (4) with a torsion angle (C(ipso)1-Centroid1-Centroid2-C(ipso)2) of phi = 63.5 degrees . The angles between the ligand planes are 2.2, 3.9 and 1.8 degrees , respectively. The Cr atom is slightly (by 0.04-0.06 A) displaced towards the substituents from the line connecting the centers of the opposite aromatic rings. The Cr-C(ipso) distances are 2.115 (2)-2.137 (2), 2.112 (2) and 2.185 (3) A for CN, CF(3) and CH(3) groups, respectively. The CN groups as well as the H atoms lie out of the C(6) ring planes and are bent towards the Cr atom, but the C atom of the CH(3) group also lying out of the C(6) ring plane is bent away from the Cr atom. The C atom of the CF(3) group is essentially coplanar to the C(6) ring plane. There are no unusual intermolecular contacts in the structures of (2)-(4).

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“…(4) Would triplet structures with 17-electron vanadium configurations, similar to the 17-electron vanadium configuration in the known doublet V(CO) 6 , be energetically competitive with singlet structures having 18-electron vanadium configurations. Singlet structures with formally coordinately unsaturated 16-electron configurations also appear reasonable for early transition metal derivatives as indicated by the stability of the 16-electron complexes (g 5 -C 5 H 5 ) (g 7 -C 7 H 7 )Ti [12], (g 5 -C 5 H 5 ) 2 Ti(CH 3 ) 2 [13], and (g 6 -CH 3 C 6 H 5 ) 2 Ti [14].…”

Section: Introductionmentioning

confidence: 89%

The oxophilicity of vanadium in unsaturated homoleptic binuclear vanadium carbonyl structures

King

Schaefer

Liu

et al. 2008

Journal of Organometallic Chemistry

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Structure, spectra and chemical properties of ditoluenetitanium

Cited by 29 publications

References 1 publication

Metal−Ligand Bonding and Bonding Energetics in Zerovalent Lanthanide, Group 3, Group 4, and Group 6 Bis(arene) Sandwich Complexes. A Combined Solution Thermochemical and ab Initio Quantum Chemical Investigation

Metal−Ligand Bonding and Bonding Energetics in Zerovalent Lanthanide, Group 3, Group 4, and Group 6 Bis(arene) Sandwich Complexes. A Combined Solution Thermochemical and ab Initio Quantum Chemical Investigation

Substituent effects in bis(arene)chromium compounds containing a CN group in the aromatic ring

The oxophilicity of vanadium in unsaturated homoleptic binuclear vanadium carbonyl structures

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