Detail of "3559-74-8"

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Natural bond orbital (NBO) analysis of the metallotropic shifts in cyclopentadienyl(trimethyl)silane, -germane and -stannane

All Rights Reserved. Natural bond orbital (NBO) analysis of the metallotropic shifts in cyclopentadienyl(trimethyl)silane, -germane and -stannane. Nori-Shargh, Davood; Roohi, Fahimeh; Deyhimi, Farzad; Naeem-Abyaneh, Reza (Chemistry Department, Graduate Faculty, Arak Branch, Islamic Azad University, Arak, Iran). Lecture Series on Computer and Computational Sciences, 4 A(Advances in Computational Methods in Sciences and Engineering), 433-435 (English) 2005 Brill Academic Publishers. CODEN: LSCCAR. ISSN: 1573-4196. DOCUMENT TYPE: Journal CA Section: 29 (Organometallic and Organometalloidal Compounds) Section cross-reference(s): 22 NBO//B3LYP/3-21G, NBO//B3LYP/3-21G* and NBO//B3LYP/LANL2DZ* anal. was used to investigate the aptitude of the alkyl and metallotropic 1,2-shifts in 5-tert-butylcyclopentadiene (1), cyclopentadienyl(trimethyl)silane (2), cyclopentadienyl(trimethyl)germane (3) and cyclopentadienyl(trimethyl)stannane (4). B3LYP/3-21G, B3LYP/3-21G* and B3LYP/LANL2DZ* results show that the MMe3 (M = Si (2), Ge (3) and Sn (4)) migration barrier heights around cyclopentadienyl rings in compds. 1-4 decrease in following order: 4 < 3 < 2 < 1. The NBO anal. 2726-34-3 and 3559-74-8 are cas registry numbers. These chemicals are also mentioned in this article. of donor-acceptor (bond-antibond) interactions revealed that the hyperconjugation between sCcyclpentadienyl-M (M = Si (2), Ge (3) and Sn (4)) and p*C:C of cyclopentadienyl ring (s?p*) facilitate the metal migration around cyclopentadienyl ring. The donor-acceptor interactions resulted in decreasing of occupancy of sCcyclopentadienyl-M bonding orbital of C5-M bonds of the idealized Lewis structure in following order: 4 < 3 < 2 < 1, and also increasing occupancy of p*cyclopentadienyl anti-bonding orbital of C1-C2 and C3-C4 bonds of cyclopentadienyl rings in following order: 4 > 3 > 2 > 1, as calcd. by NBO//B3LYP/3-21G, NBO//B3LYP/3-21G* and NBO//B3LYP/LANL2DZ*. The results suggest that in compds. 1-4, the metallotropic shifts is controlled by s?p* energetic stabilization. The delocalization energies from sC-M bonding orbital to p*C=C antibonding orbital of cyclopentadienyl ring in compds. 1-4 are 1.45, 7.24, 7.63 and 12.49 kcal.mol-1, resp., as calcd. by B3LYP/3-21G level of theory. Also, B3LYP/3-21G* results show that the delocalization energies from sC-M bonding orbital to p*C:C antibonding orbital of cyclopentadienyl ring in compds. 1-4 are 1.45, 6.58, 9.18 and 14.11 kcal.mol-1. Further, B3LYP/LANL2DZ* results show that the above delocalization energies in compds. 1-4 are 1.26, 6.08, 8.86 and 13.47 kcal.mol-1, resp. .

Bis[dicarbonyl(cyclopentadienyl)ruthenium(I)] complexes

Bis[dicarbonyl(cyclopentadienyl)ruthenium(I)] complexes. Schumann, Herbert; Stenz, Susanne; Girgsdies, Frank; Muhle, Stefan H. (Institut fuer Chemie, Technische Universitaet Berlin, Berlin D-10623, Germany). Zeitschrift fuer Naturforschung, B: Chemical Sciences, 57(9), 1017-1026 (German) 2002 Verlag der Zeitschrift fuer Naturforschung. CODEN: ZNBSEN. ISSN: 0932-0776. DOCUMENT TYPE: Journal CA Section: 29 (Organometallic and Organometalloidal Compounds) Section cross-reference(s): 75 The prepn., crystal structure and cis-trans-isomerism of the nine title compds. is described. Ru3(CO)12 reacts with 1-R1-2-R2-3-R3-4-R4-5-R5-2,4-cyclopentadiene (Cp#, 1-9; 1, R1 = Me3C, R2-R5 = H; 2, R1 = Me3Si, R2-R5 = H; 3, R1 = Me3C, R3 = Me, R2, R4, R5 = H; 4, R1, R3 = Me3C, R2, R4, R5 = H; 5, R1 = Me2CH, R2-R5 = Me; 6, R1 = Me3C, R2-R5 = Me; 7, R1 = Ph, R2-R5 = Me; 8, R1, R3, R4 = H, R2, R5 = Ph; 9, R1 = H, R2-R5 = Ph), with formation of the corresponding bis[dicarbonyl(cyclopentadienyl) ruthenium(I)] complexes [RuCp#(CO)2]2 1a-9a. The 1H and 13C NMR spectra of the new compds. 3a and 5a to 9a as well as the single crystal x-ray structures of 1a, 4a, 5a, 7a, 8a, and 9a are reported and discussed. According to crystallog., NMR and IR data, complexes 1a-3a, 5a-7a adopt trans-configuration across the Ru-Ru bond, whereas 8a and 9a have cis-configuration in crystal state. Complex 4a exists in crystal state as 1:2 mixt. 3559-74-8 which is the cas registry number of one of substances is just one of reagents here. of cis- and trans-isomers. All complexes 1a-9a possess two bridged m-CO groups. .