title: A combined experimental and theoretical study of the tautomeric and conformational properties of (5-phenyl-tetrazol-2-yl)-acetic acid methyl ester.
abstract: The tautomeric and conformational properties of a new tetrazole derivative are studied in a combined approach that includes the analysis of the experimental vibrational data together with theoretical calculation methods, especially in terms of natural bond orbital (NBO) population analysis. Moreover, the molecular and crystal structure was determined by single crystal X-ray diffraction. The compound crystallized as the 2-tautomeric form, monoclinic space group P21/c with Z=4, a=10.0630(14), b=8.2879(11), c=12.8375(18) Å, β=105.546(3)°, V=1031.5(2) Å(3). The tetrazole and phenyl rings are coplanar with the acetate group oriented perpendicular to the plane. The NBO analysis showed that delocalizing interactions of the lpp(N2) lone pair orbital contributes to a strong resonance interactions with both adjacent π(∗)(N3N4) and π(∗)(N1C5) antibonding orbitals of the tetrazole group.
authors.affiliation: Department of Chemistry, Quaid-I-Azam University, Islamabad 45320, Pakistan. Electronic address: aamersaeed@yahoo.com.
authors.forename: Aamer
authors.initials: A
authors.lastname: Saeed
authors.affiliation: Department of Chemistry, Quaid-I-Azam University, Islamabad 45320, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Qasim
authors.affiliation: Department of Chemistry, Quaid-I-Azam University, Islamabad 45320, Pakistan.
authors.forename: Majid
authors.initials: M
authors.lastname: Hussain
authors.affiliation: Department Chemie, Fakultät fur Naturwissenschaften, Universitat Paderborn, Warburgerstrasse 100, D-33098 Paderborn, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Flörke
authors.affiliation: CEQUINOR (UNLP, CONICET-CCT La Plata), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 962, 1900 La Plata, Argentina. Electronic address: erben@quimica.unlp.edu.ar.
authors.forename: Mauricio F
authors.initials: MF
authors.lastname: Erben
mesh_terms: D000085:Acetates / Q000737:chemistry*; D018360:Crystallography, X-Ray; D007536:Isomerism; D008958:Models, Molecular; D008968:Molecular Conformation; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared; D013777:Tetrazoles / Q000737:chemistry*
chemical_list: D000085:Acetates; D013777:Tetrazoles; C045574:1H-tetrazole; C046923:methyl acetate
keywords: Conformational analysis; Crystal structure; Quantum chemical calculations; Tautomerism; Tetrazole; Vibrational spectroscopy