Frontier orbital interactions of electron pushing and drawing substituents with ferrocenyl group

1997 ◽  
Vol 40 (3) ◽  
pp. 236-244 ◽  
Author(s):  
Yueshun Jiang ◽  
Xiangdong Chai ◽  
Wensheng Yang ◽  
Dong Zhang ◽  
Yunwei Cao ◽  
...  
Keyword(s):  
Frontier Orbital ◽  
Orbital Interactions ◽  
Ferrocenyl Group

Importance of frontier orbital interactions in addition reaction of water to disilene

2001 ◽  
Vol 84 (2) ◽  
pp. 192-197 ◽  
Author(s):  
Masae Takahashi ◽  
Tamás Veszprémi ◽  
Mitsuo Kira
Keyword(s):  
Addition Reaction ◽  
Frontier Orbital ◽  
Orbital Interactions

Cycloadditions of Nitrile Oxides to α,β-Unsaturated Aldehydes. Frontier Orbital Interactions and Secondary Orbital Interactions at Work in Determining Regiochemistry

Tetrahedron ◽  
2000 ◽  
Vol 56 (25) ◽  
pp. 4299-4309 ◽  
Author(s):  
Lucio Toma ◽  
Paolo Quadrelli ◽  
Giancarlo Perrini ◽  
Remo Gandolfi ◽  
Cristiana Di Valentin ◽  
...  
Keyword(s):  
Frontier Orbital ◽  
Orbital Interactions ◽  
Nitrile Oxides ◽  
Unsaturated Aldehydes

Frontier orbital interactions in the hetero Diels–Alder cycloaddition of diazadienes

2008 ◽  
Vol 86 (5) ◽  
pp. 384-394 ◽  
Author(s):  
Pratibha Sharma ◽  
Ashok Kumar ◽  
Vinita Sahu ◽  
Jitendra Singh
Keyword(s):  
Chemical Potential ◽  
Molecular Orbital Calculation ◽  
Diels Alder ◽  
Reaction Pathways ◽  
Electronic Charge ◽  
Chemical Hardness ◽  
Frontier Orbital ◽  
Electrophilicity Index ◽  
Reactivity Pattern ◽  
Orbital Interactions

This work deals with the molecular orbital calculation studies performed on different diazadienes to assess their reactivity pattern. The interaction of these diazadienes with various electron-poor and electron-rich dienophiles leads to the formation of diazines and tetrazines as the cycloadducts. The results from frontier orbital interactions were used to rationalize the reactivity and predictability of NDAC and IEDDAC reaction pathways. Correlation studies were also performed to predict reactivity sequence using a number of electronic descriptors, such as electrophilicity index (ω), chemical potential (µ), electronic charge ΔNmax, and chemical hardness η. Moreover, these studies exhibit good compatibility with experimental observations.Key words: AM1, MNDO, PM3, diazadienes, tetrazines, electrophilicity index, chemical potential.

Theoretical studies of SN2 transition states. Substituent effects

1982 ◽  
Vol 60 (11) ◽  
pp. 1291-1294 ◽  
Author(s):  
Saul Wolfe ◽  
David John Mitchell ◽  
H. Bernhard Schlegel
Keyword(s):  
Gas Phase ◽  
Transition States ◽  
Substituent Effects ◽  
Orbital Interaction ◽  
Frontier Orbital ◽  
Orbital Interactions ◽  
Pyramidal Inversion ◽  
New Type ◽  
Constraint Effects ◽  
And Inversion

Similar substituent and angular constraint effects are noted for pyramidal inversion at tricoordinate nitrogen and inversion at a carbon centre undergoing an SN2 displacement reaction. The former process has been analyzed successfully by a quantitative PMO analysis which focuses on the frontier orbital interactions between X and NH2 in the planar and pyramidal structures of X—NH2 molecules having X = F, CH3, CHO. Based on total energy calculations at the 6-311G*//4-31G level, the effects of X upon the rates of the gas phase SN2 reactions F− + XCH2F → XCH2F + F− are found to be [Formula: see text]. Taking the treatment of nitrogen inversion as a precedent, the origin of this trend has been examined by a quantitative PMO analysis which focuses on the frontier orbital interactions between X and CH2F2− in the transition states, and between X and CH2F in the reactants. This has revealed that the rate enhancement associated with an α-carbonyl substituent in these SN2 reactions can be related to the presence of a stabilizing orbital interaction of a new type in the transition state, coupled to an exceptionally low destabilizing orbital interaction.

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