title: Importance of weak interactions in developing 1,3-bis(4,6-dimethyl-1H-nicotinonitrile-1-yl)1,3-dioxy propane polymorphs.
abstract: The structure of 1,3-bis(4,6-dimethyl-1H-nicotinonitrile-1-yl)1,3-dioxy propane polymorphs has been characterized by X-ray diffraction, FT-IR, 1H and 13C NMR spectroscopies. The influence of intra and intermolecular weak interactions is thoroughly studied in solid state using single crystal X-ray diffraction and FT-IR. These polymorphs belong to monoclinic space group 'P2(1/n)' and 'P2(1/c)'. These polymorphs have C-H⋯n (lone pair), hydrogen bonds, C-N⋯π, C-H⋯π and π⋯π intermolecular non-covalent interactions. These polymorphs are the result of weak interactions and solvent used in crystallization. The FT-IR spectra have been recorded in the solid phase and NMR has been recorded in solvent. The optimized geometry has been calculated by B3LYP methods using different basis sets. The FT-IR and NMR spectra of 1st polymorphs has been calculated at B3LYP/6-31G (d) level. The scaled theoretical wave number showed good agreement with the experimental values. These two polymorphs as well as other stereomers are studied by DFT calculations.
authors.affiliation: Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221 005, India. tashish2002@yahoo.com
authors.forename: Ashish Kumar
authors.initials: AK
authors.lastname: Tewari
authors.forename: Ved Prakash
authors.initials: VP
authors.lastname: Singh
authors.forename: Rashmi
authors.initials: R
authors.lastname: Dubey
authors.forename: Carmen
authors.initials: C
authors.lastname: Puerta
authors.forename: Pedro
authors.initials: P
authors.lastname: Valerga
authors.forename: Rajnikant
authors.initials: R
authors.lastname: Verma
mesh_terms: D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009539:Nicotinic Acids / Q000737:chemistry* / Q000378:metabolism*; D009570:Nitriles / Q000737:chemistry* / Q000378:metabolism*; D011407:Propane / Q000737:chemistry* / Q000378:metabolism*; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D014732:Vibration; D014961:X-Ray Diffraction
chemical_list: C568097:1,3-bis(4,6-dimethyl-1H-nicotinonitrile-1-yl)1,3-dioxy propane; D009539:Nicotinic Acids; D009570:Nitriles; D011407:Propane