Synthesis, molecular and electronic structure of a stacked half-sandwich dititanium complex incorporating a cyclic pi-faced bridging ligand

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F16%3A10331119" target="_blank" >RIV/00216208:11310/16:10331119 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1039/c6ra14940e" target="_blank" >http://dx.doi.org/10.1039/c6ra14940e</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c6ra14940e" target="_blank" >10.1039/c6ra14940e</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Synthesis, molecular and electronic structure of a stacked half-sandwich dititanium complex incorporating a cyclic pi-faced bridging ligand

Popis výsledku v původním jazyce

A thermally robust triple-decker complex [bis(eta(5)-pentamethylcyclopentadienyltitanium)-mu-(eta(4):eta(4) -1,2,4,5tetrakis(trimethylsilyl) cyclohexa-1-4-diene-3,6-diyl)] (3) was obtained in 4% yield by thermolysing Cp*TiMe3 in the presence bis(trimethylsilyl) acetylene (BTMSA). The solid-state structure of centrosymmetric 3 features rather long all C-C bonds in the nearly planar bridging ligand (1.4720(14)1.4896(15) angstrom) and a short distance of its least-square plane to the titanium atoms (1.7381(5) angstrom). Computational results revealed the bonding of the central ligand to be accomplished through back-bonding of its two C=C bonds and through the simultaneous generation of two s sigma-Ti-C(H) bonds. Based on CASSCF and CASPT2 results, the molecule acquires several electronic configurations simultaneously, which hinders its representation by one single Lewis structure. Apart from being coordinated to the central ligand, the metal atoms are involved in a direct Ti-Ti bonding by the formation of one sigma- and two delta-bonds between them. The bond order of this Ti-Ti overlap shows only a slight decrease upon electronic excitation. The presence of ionic contribution to the bonding of the central ligand is manifested by the charge -1.4e summed on the carbon atoms of the bridging ring. Based on computational results, the spin multiplicity of the ground state is singlet, while the first low lying excitation state is triplet. This is in agreement with the absence of EPR signal in either toluene solution and glass, and with slight downfield shifts of broadened H-1 NMR signals of SiMe3 and Cp* methyl groups observed with increasing temperature.

Název v anglickém jazyce

Synthesis, molecular and electronic structure of a stacked half-sandwich dititanium complex incorporating a cyclic pi-faced bridging ligand

Popis výsledku anglicky

A thermally robust triple-decker complex [bis(eta(5)-pentamethylcyclopentadienyltitanium)-mu-(eta(4):eta(4) -1,2,4,5tetrakis(trimethylsilyl) cyclohexa-1-4-diene-3,6-diyl)] (3) was obtained in 4% yield by thermolysing Cp*TiMe3 in the presence bis(trimethylsilyl) acetylene (BTMSA). The solid-state structure of centrosymmetric 3 features rather long all C-C bonds in the nearly planar bridging ligand (1.4720(14)1.4896(15) angstrom) and a short distance of its least-square plane to the titanium atoms (1.7381(5) angstrom). Computational results revealed the bonding of the central ligand to be accomplished through back-bonding of its two C=C bonds and through the simultaneous generation of two s sigma-Ti-C(H) bonds. Based on CASSCF and CASPT2 results, the molecule acquires several electronic configurations simultaneously, which hinders its representation by one single Lewis structure. Apart from being coordinated to the central ligand, the metal atoms are involved in a direct Ti-Ti bonding by the formation of one sigma- and two delta-bonds between them. The bond order of this Ti-Ti overlap shows only a slight decrease upon electronic excitation. The presence of ionic contribution to the bonding of the central ligand is manifested by the charge -1.4e summed on the carbon atoms of the bridging ring. Based on computational results, the spin multiplicity of the ground state is singlet, while the first low lying excitation state is triplet. This is in agreement with the absence of EPR signal in either toluene solution and glass, and with slight downfield shifts of broadened H-1 NMR signals of SiMe3 and Cp* methyl groups observed with increasing temperature.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

CF - Fyzikální chemie a teoretická chemie

OECD FORD obor

—

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

RSC Advances

ISSN

2046-2069

e-ISSN

—

Svazek periodika

6

Číslo periodika v rámci svazku

96

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

11

Strana od-do

94149-94159

Kód UT WoS článku

000385631900111

EID výsledku v databázi Scopus

2-s2.0-84991107684