نتایج جستجو برای: axial and equatorial position

تعداد نتایج: 16855566  

Davood Nori-Shargh, Hooriye Yahyaei Nasrin Masnabadi Seiedeh Negar Mousavi Zahra Mahmoodi

The conformational behaviors of 2,3-bis(methylthio)-1,4-dioxane (1), 2,3-bis(methylthio)-1,4-dithiane (2) and 2,3-bis(methylthio)-1,4-diselenane (3) have been analyzed by means ofhybrid-density functional theory (B3LYP/Def2-TZVPP) based method and NBO interpretation.B3LYP/Def2-TZVPP results showed that the axial conformations of compounds 1-3 are morestable than their equatorial conformations. ...

NBO analysis, hybrid density functional theory (B3LYP/6-311+G**) and ab initio molecular orbital (HF/6-311+G**) based methods were used to study the anomeric effects (AE), electrostatic interactions, dipole-dipole interactions and steric repulsion effects on the conformational properties of 2-methoxy- (1), 2-methylthio- (2), 2-methylseleno- (3), 2-fluoro- (4), 2-chloro- (5) and 2-bromocyclohexa...

Journal: :Acta crystallographica. Section E, Crystallographic communications 2016
Saloua Chelli Konstantin Troshin Sami Lakhdar Herbert Mayr Peter Mayer

In the title compound, C23H25ClO4, the cyclo-hexane ring adopts a chair conformation with the 4-meth-oxy-phenyl substituent in an axial position and the chloro-(4-meth-oxy-phen-yl)methyl substituent in an equatorial position. The packing features inversion dimers formed by pairs of C-H⋯O contacts and strands along [100] and [010] established by further C-H⋯O and C-H⋯Cl contacts, respectively.

2001
James M. Howell Earl L. Muetterties

The electronic structure of some idealized PH5 geometries of D3h, C4v, and C, symmetries is analyzed. Each geometry is characterized by a low-lying nodeless orbital, three singly noded orbitals close in energy, and a high-lying doubly noded nonbonding orbital. The latter orbital is the only one significantly stabilized by the inclusion of 3d orbitals in the P basis set and also determines the r...

2009
Hossein Rahmani Hooshang Pirelahi Seik Weng Ng

The six-membered thio-pyran ring in the title compound, C(26)H(24)S, adopts a boat conformation, with the S atom displaced by 0.478 (2) Å and the 3-methyl-ene C atom by 0.644 (2) Å from the plane of the other four sp(2)-hydridized C atoms. The methyl group on the methyl-ene carbon lies in a pseudo-equatorial position and the phenyl ring in a pseudo-axial position.

2009
Hossein Rahmani Hooshang Pirelahi Seik Weng Ng

The six-membered thio-pyran ring in the title compound, C(24)H(19)BrS, adopts an approximate envelope conformation, with the S atom displaced by 0.26 (1) Å and the 2-methyl-ene C atom by -0.54 (1) Å from the plane of the other four sp(2)-hydridized C atoms. The methyl substituent on the methyl-ene carbon lies in a pseudo-axial position with the phenyl ring in a pseudo-equatorial position.

2010
Wei Chen Miao Yu Si Li Ning Jiao

In the title compound, C(19)H(24)O(4), the six-membered lactone ring adopts an envelope conformation with the tert-butoxy-carbonyl and isopropyl substituents in axial positions, and the phenyl group in an equatorial position. In the crystal structure, weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into centrosymmetric dimers.

Journal: :journal of the iranian chemical research 0
davood nori-shargh department of chemistry, arak branch, islamic azad university, arak, iran sogand sarikhani department of chemistry, arak branch, islamic azad university, arak, iran hooriye yahyaei department of chemistry, zanjan branch, islamic azad university, zanjan, iran seiedeh negar mousavi department of chemistry, arak branch, islamic azad university, arak, iran nasrin masnabadi department of chemistry, roudehen branch, islamic azad university, roudehen, iran

nbo analysis and density functional theory (dft: b3lyp/6-311+g**) based method were used to study the impacts of the anomeric effects (ae) on the conformational properties of 2-methoxy-1,2,4,5-tetrahydro-benzo[d]oxepine (1), -thiepine (2) and -selenepine (3). the gibbs free energy difference (geq–gax) values (i.e. δgeq-ax) at 298.15 k and 1 atm between the axial and equatorial conformations inc...

2009
Hossein Chiniforoshan Soghra Jalilpour Bahare Shirinfar Hamid Reza Khavasi

In the title compound, [Cu(C(7)H(4)N(3)O(2))(2)(C(3)H(7)NO)], the Cu(II) atom is five-coordinated in a distorted square-pyramidal geometry, with the N atoms in equatorial positions and the dimethyl-formamide O atom in an axial position. The dihedral angle between adjacent benzene rings is 70.33 (12)°.

Journal: :Chemical & Pharmaceutical Bulletin 2021

The addition of an aqueous solution diketopiperazine cyclo(Pro-Xxx) (Xxx: amino acid residue) to (?)-epigallocatechin-3-O-gallate (EGCg) led precipitation the complex EGCg and cyclo(Pro-Xxx). molecular capture abilities using were evaluated by ratio amount included in precipitates with that total used. Stronger hydrophobicity side chain residue a higher ability. Furthermore, ability decreased w...

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