Decamethyltitanocene hydride intermediates in the hydrogenation of the corresponding titanocene-(eta(2)-ethene) or (eta(2)-alkyne) complexes and the effects of bulkier auxiliary ligands
Identifikátory výsledku
Kód výsledku v IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F17%3A00482774" target="_blank" >RIV/61388955:_____/17:00482774 - isvavai.cz</a>
Nalezeny alternativní kódy
RIV/00216208:11310/17:10361032
Výsledek na webu
<a href="http://dx.doi.org/10.1039/c7dt01545c" target="_blank" >http://dx.doi.org/10.1039/c7dt01545c</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1039/c7dt01545c" target="_blank" >10.1039/c7dt01545c</a>
Alternativní jazyky
Jazyk výsledku
angličtina
Název v původním jazyce
Decamethyltitanocene hydride intermediates in the hydrogenation of the corresponding titanocene-(eta(2)-ethene) or (eta(2)-alkyne) complexes and the effects of bulkier auxiliary ligands
Popis výsledku v původním jazyce
H-1 NMR studies of reactions of titanocene [Cp*Ti-2] (Cp*=eta(5)-C5Me5) and its derivatives [Cp*(eta(5):eta(1)-C5Me4CH2)TiMe] and [Cp*Ti-2(eta(2)-CH2=CH2)] with excess dihydrogen at room temperature and pressures lower than 1 bar revealed the formation of dihydride [Cp*2TiH2] (1) and the concurrent liberation of either methane or ethane, depending on the organometallic reactant. The subsequent slow decay of 1 yielding [Cp*2TiH] (2) was mediated by titanocene formed in situ and controlled by hydrogen pressure. The crystalline products obtained by evaporating a hexane solution of fresh [Cp*Ti-2] in the presence of hydrogen contained crystals having either two independent molecules of 1 in the asymmetric part of the unit cell or cocrystals consisting of 1 and [Cp*Ti-2] in a 2 : 1 ratio. Hydrogenation of alkyne complexes [Cp*Ti-2(eta(2)-(RC)-C-1 CR2)] (R-1 = R-2 = Me or Et) performed at room temperature afforded alkanes (RCH2CH2R2)-C-1, and after removing hydrogen, 2 was formed in quantitative yields. For alkyne complexes containing bulkier substituent(s) R-1 = Me or Ph, R-2 = SiMe3, and R-1 = R-2 = Ph or SiMe3, successful hydrogenation required the application of increased temperatures (70-80 degrees C) and prolonged reaction times, in particular for bis(trimethylsilyl)acetylene. Under these conditions, no transient 1 was detected during the formation of 2. The bulkier auxiliary ligands eta(5)-(CMe4Bu)-Me-5-Bu-t and eta(5)-C5Me4SiMe3 did not hinder the addition of dihydrogen to the corresponding titanocenes [(eta(5)-(C5Me4Bu)-Bu-t)(2)Ti] and [(eta(5)-C5Me4SiMe3) Ti-2] yielding [(eta(5)-(C5Me4Bu)-Bu-t)(2)TiH2] (3) and [(eta(5)-C5Me4SiMe3)(2)TiH2] (4), respectively. In contrast to 1, the dihydride 4 did not decay with the formation of titanocene monohydride, but dissociated to titanocene upon dihydrogen removal...
Název v anglickém jazyce
Decamethyltitanocene hydride intermediates in the hydrogenation of the corresponding titanocene-(eta(2)-ethene) or (eta(2)-alkyne) complexes and the effects of bulkier auxiliary ligands
Popis výsledku anglicky
H-1 NMR studies of reactions of titanocene [Cp*Ti-2] (Cp*=eta(5)-C5Me5) and its derivatives [Cp*(eta(5):eta(1)-C5Me4CH2)TiMe] and [Cp*Ti-2(eta(2)-CH2=CH2)] with excess dihydrogen at room temperature and pressures lower than 1 bar revealed the formation of dihydride [Cp*2TiH2] (1) and the concurrent liberation of either methane or ethane, depending on the organometallic reactant. The subsequent slow decay of 1 yielding [Cp*2TiH] (2) was mediated by titanocene formed in situ and controlled by hydrogen pressure. The crystalline products obtained by evaporating a hexane solution of fresh [Cp*Ti-2] in the presence of hydrogen contained crystals having either two independent molecules of 1 in the asymmetric part of the unit cell or cocrystals consisting of 1 and [Cp*Ti-2] in a 2 : 1 ratio. Hydrogenation of alkyne complexes [Cp*Ti-2(eta(2)-(RC)-C-1 CR2)] (R-1 = R-2 = Me or Et) performed at room temperature afforded alkanes (RCH2CH2R2)-C-1, and after removing hydrogen, 2 was formed in quantitative yields. For alkyne complexes containing bulkier substituent(s) R-1 = Me or Ph, R-2 = SiMe3, and R-1 = R-2 = Ph or SiMe3, successful hydrogenation required the application of increased temperatures (70-80 degrees C) and prolonged reaction times, in particular for bis(trimethylsilyl)acetylene. Under these conditions, no transient 1 was detected during the formation of 2. The bulkier auxiliary ligands eta(5)-(CMe4Bu)-Me-5-Bu-t and eta(5)-C5Me4SiMe3 did not hinder the addition of dihydrogen to the corresponding titanocenes [(eta(5)-(C5Me4Bu)-Bu-t)(2)Ti] and [(eta(5)-C5Me4SiMe3) Ti-2] yielding [(eta(5)-(C5Me4Bu)-Bu-t)(2)TiH2] (3) and [(eta(5)-C5Me4SiMe3)(2)TiH2] (4), respectively. In contrast to 1, the dihydride 4 did not decay with the formation of titanocene monohydride, but dissociated to titanocene upon dihydrogen removal...
Klasifikace
Druh
J<sub>imp</sub> - Článek v periodiku v databázi Web of Science
CEP obor
—
OECD FORD obor
10403 - Physical chemistry
Návaznosti výsledku
Projekt
Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.
Návaznosti
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Ostatní
Rok uplatnění
2017
Kód důvěrnosti údajů
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Údaje specifické pro druh výsledku
Název periodika
Dalton Transactions
ISSN
1477-9226
e-ISSN
—
Svazek periodika
46
Číslo periodika v rámci svazku
25
Stát vydavatele periodika
GB - Spojené království Velké Británie a Severního Irska
Počet stran výsledku
6
Strana od-do
8229-8244
Kód UT WoS článku
000404467500028
EID výsledku v databázi Scopus
2-s2.0-85021739743