کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1406799 | 1501872 | 2008 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Molecular structure and conformation of phenylacetyl chloride as obtained by gas-phase electron diffraction and theoretical calculations
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The structure and conformation of phenylacetyl chloride, PhCH2(CO)Cl, has been determined by gas-phase electron diffraction (GED), using results from ab initio calculations (HF and MP2/6-311 + G(d,p)) to obtain restraints on some of the structural parameters. The molecules exist in the gas-phase (118 °C) as a mixture of two stable conformers; syn with CO eclipsing CalkylCphenyl and gauche with CO eclipsing CH. For both conformers the phenyl ring is about 90-120° out of the plane of the acetyl group. The experimentally observed conformational composition was 75(8)% gauche and 25(8)% syn (parenthesised values are 2Ï). Using theoretical values for the entropy difference between conformers, including the fact that there are two identical gauche forms, this composition corresponds to an enthalpy difference of ÎH°(gauche-syn) = â0.8(12) kJ molâ1. The results for the principal distances (ra) and angles (â h1) for the gauche conformer obtained from the combined GED/ab initio study (2Ï uncertainties) are: r(CH)phenyl = 1.078(6) Ã
, r(CH)alkyl = 1.089(12) Ã
, r(CO)Â =Â 1.180(6)Â Ã
, r(CC)phenyl = 1.396(4) Ã
(average value), r(CphenylCalkyl)Â =Â 1.509(16)Â Ã
, r(CalkylCcarbonyl)Â =Â 1.513(12)Â Ã
, r(CCl)Â =Â 1.780 (6)Â Ã
, â CphenylCalkylCcarbonyl = 110.6(12)°, â CCO = 125.5(8)°, â CCCl = 113.3(6)°, â CCHphenyl = 119.9(2)° (average value), â CphenylCalkyl H = 110.8(2)° (average value), Ï(CCCC) = 118(4)°, Ï(CCCO) = 95(2)°.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure - Volume 892, Issues 1â3, 15 December 2008, Pages 373-377
Journal: Journal of Molecular Structure - Volume 892, Issues 1â3, 15 December 2008, Pages 373-377
نویسندگان
Kirsten Aarset, Kolbjørn Hagen,