An experimental and theoretical study of vibrational spectra of picolinamide, nicotinamide, and isonicotinamide

Bakiler, Meriç; Bölükbaşı, Olcay; Yılmaz, Ayberk

doi:10.1016/j.molstruc.2006.04.021

Cited by 52 publications

(42 citation statements)

References 15 publications

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“…The results of the DFT calculations (three different basis sets) of the molecular structure for the N,N 0 conformer of picolinamide [30] are also consistent with that found in the present article for MPCA. Recently published data for the picolinamide molecule in the temperature of ca.…”

Section: Structure Of the N-methyl-2-pyridinecarboxyamide (Mpca)supporting

confidence: 90%

Tricarbonyltechnetium(I) and tricarbonylrhenium(I) complexed with N-methyl-2-pyridinecarboxyamide as potential radiopharmaceuticals: a computational study

2010

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The electronic and thermodynamic properties of the '2 ? 1' tricarbonyltechnetium(I) and -rhenium(I) mixed ligand complexes with N-methylpyridine-2-carboxyamide (MPCA) as a bidentate ligand and chloride, water, or tert-butyl-3-isocyanopropanoate (BCP), were investigated within the framework of Density Functional Theory. The atomic charges of all complexes, polarization of the CO groups, as well as the effect of transfer of p-electron density between the ligands through the metal were calculated and compared. The free energies of the reaction of formation of the isocyanide complexes in aqueous solution were calculated based on calculated total free energies in aqueous solution of the products and the substrates. The dissociation energies of the complexes were also determined in order to rationalize the experimentally observed higher resistance of the rhenium compared to the technetium complexes in the challenge experiments with the standard sulfur-containing amino acids.

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Section: Structure Of the N-methyl-2-pyridinecarboxyamide (Mpca)supporting

confidence: 90%

Tricarbonyltechnetium(I) and tricarbonylrhenium(I) complexed with N-methyl-2-pyridinecarboxyamide as potential radiopharmaceuticals: a computational study

2010

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“…12 Form II gives a peak at 991 cm À1 while forms I and IV show a peak maximum at, respectively, 995 and 997 cm…”

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confidence: 98%

Isonicotinamide self-association: the link between solvent and polymorph nucleation

et al. 2012

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We show that, in a controlled and reproducible way, specific solvents lead to specific polymorphic forms of isonicotinamide. We argue on the basis of Raman and FTIR spectroscopy that the hydrogen bonding in solution kinetically drives the nucleation towards a specific form. This generally may lead to good understanding and control of polymorphism and crystal nucleation.The ability to control and predict crystal nucleation is of paramount importance from the viewpoint of crystal engineering, materials synthesis and crystalline product quality. [1][2][3] In this communication we demonstrate the reproducible effect of solvents on the formation of isonicotinamide (INA) polymorphs. We establish that in solvents with strong hydrogen bond acceptors, the dominant configuration of the INA molecules with respect to each other is that of amide-pyridine heterosynthons (headto-tail chains) (Fig. 1). Similarly, solvents with strong hydrogen bond donors lead to dominancy of amide-amide homosynthons (head-to-head dimers). This self-association in solution controls the polymorph nucleation of INA by controlling the building unit attaching to the nucleus.Polymorphism can be defined as the ability of a single chemical compound to form more than one crystal structure. 4 Polymorphism of active pharmaceutical ingredients is the subject of intense interest in both science and industry. 4,5 On the one hand, this is because crystalline product quality aspects such as drug efficacy, bioavailability and safety are affected by the polymorphic form present. On the other hand, polymorphs have economic and intellectual property implications.Often through empirical research, effects of solvent, supersaturation and impurities are observed on polymorph formation. 6 Recently, next to the two known forms of INA, 7 a third form was reported which incidentally and irreproducibly formed during a co-crystal screen from a multicomponent solution. 8 More recently, the difficult to control evaporative crystallization process yielded two new forms of INA.9 Form IV was obtained only as a mixture together with form II and/or V. For form V yields were often poor, typically 10%, and in some cases it could not be obtained.The crystal nucleation of INA is a most interesting process because of the strongly differing packing of form II and the other forms (ESIw). Isonicotinamide form II has been reported to be the most stable form at room temperature. 8 In the structure of form II the amide groups form homosynthons (dimers), 8 which in turn are hydrogen bonded through the oxygen atom and the remaining hydrogen of the amide group. Interestingly, the pyridine group does not participate in hydrogen bonding in the crystal structure of form II, contrary to all other currently known forms of INA. These consist of differently packed head-to-tail chains connected through heterosynthons of the amide and the pyridine group.The classical view of crystal nucleation is that building units attach to and detach from clusters of molecules.10 This attaching building unit could be...

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“…They possess a variety of pharmacological activity; among others, analgesic [1,2], antitumor [3,4], prokinetic [5], and neuroleptic [6]. Owing to medical applications and theoretical importance, extensive studies have dealt with benzamide and its derivatives [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

“…The molecular structures of heterocyclic aromatic amides have also been studied, viz., picolinamide [17], nicotinamide [17,18], and isonicotinamide [17], by DFT calculations. Comparison of X-ray diffraction [19], neutron diffraction (ND) [20], and gas-phase electron diffraction (GED) [21] results on nicotinamide has provided evidence of intermolecular hydrogen bonding in its crystal.…”

Section: Introductionmentioning

confidence: 99%

Equilibrium molecular structure of benzamide from gas-phase electron diffraction and theoretical calculations

2015

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The molecule structure of benzamide has been determined in the gas phase by electron diffraction using results from quantum chemical calculations for constraints in the analysis. The root-mean-square amplitudes of vibration and harmonic shrinkage corrections were calculated taking into account nonlinear relations between Cartesian and internal vibrational coordinates at the level of first-order perturbation theory. The corresponding r h1 structure agrees well with the results of B3LYP/cc-pVTZ calculations. To take into account vibrational effects, the corrections to the experimental r a bond lengths, the values of the differences r e -r a were obtained using quadratic and cubic force constants from ab initio calculations at the MP2/cc-pVTZ level of theory). The equilibrium structure from the experiment agrees well with the results of the ab initio calculations. The following structural parameters were obtained (bond lengths in Angstroms and bond angles in degrees with 3r in parentheses): r(C=C) av = 1.392(1), r(C-C) = 1.502(4), r(C-N) = 1.367(1), r(C=O) = 1.224 (3), r(C-H) = 1.084(4), \C6C1C2 = 119.8, \CCN = 116.8(10), \CCO = 120.8(11), \C2C1C7O = 18.4(27). The C=O bond is shorter by 0.02 Å , and the C-N bond is longer by 0.03 Å than the corresponding bonds in the crystal. These differences are ascribed to the effect of intermolecular hydrogen bonding on the structure in the crystal.

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An experimental and theoretical study of vibrational spectra of picolinamide, nicotinamide, and isonicotinamide

Cited by 52 publications

References 15 publications

Tricarbonyltechnetium(I) and tricarbonylrhenium(I) complexed with N-methyl-2-pyridinecarboxyamide as potential radiopharmaceuticals: a computational study

Tricarbonyltechnetium(I) and tricarbonylrhenium(I) complexed with N-methyl-2-pyridinecarboxyamide as potential radiopharmaceuticals: a computational study

Isonicotinamide self-association: the link between solvent and polymorph nucleation

Equilibrium molecular structure of benzamide from gas-phase electron diffraction and theoretical calculations

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