Cavities, Layers, and Channels in the Hosting Framework of Molecular Complexes Derived From Cephradine

Quantum mechanical calculations of the cephalosporin nucleus

“…The optimized orientations of the acetylamino group as expressed by the dihedral angle C8C7N20C21 for the S1-up conformer 3 correspond to the values of À155.198 3a and 26.248 3b, where the former is more stable by 7.82 kcal/mol. These orientations are in reasonably good agreement with previously reported crystallographic results: À156.798 for bis(cephradine)-2-acetonaphthone clathrate hydrate [30,31], À158.918 for bis(cefadroxil) 2,6-dihydroxynaphthalene clathrate nonahydrate [30], 30.638 for cephradine methyl 3-hydroxybenzoate clathrate [26] and 32.898 for cephradine bis(dimethylformamide) clathrate [26]. Previously reported semiempirical values for cephalotin are À145.48, À128.78, À160.38 and À107.78 at the PM3, AM1, MNDO and MINDO level of calculation, respectively [17].…”

“…Basis set 1 2 well as reported crystallographic [18,24,26,27] and semiempirical values [17]. In accordance with X-ray results, some of the predicted values are sensitive to the orientation adopted by the dihydrothiazine ring.…”

Quantum mechanical calculations of the cephalosporin nucleus

“…The optimized orientations of the acetylamino group as expressed by the dihedral angle C8C7N20C21 for the S1-up conformer 3 correspond to the values of À155.198 3a and 26.248 3b, where the former is more stable by 7.82 kcal/mol. These orientations are in reasonably good agreement with previously reported crystallographic results: À156.798 for bis(cephradine)-2-acetonaphthone clathrate hydrate [30,31], À158.918 for bis(cefadroxil) 2,6-dihydroxynaphthalene clathrate nonahydrate [30], 30.638 for cephradine methyl 3-hydroxybenzoate clathrate [26] and 32.898 for cephradine bis(dimethylformamide) clathrate [26]. Previously reported semiempirical values for cephalotin are À145.48, À128.78, À160.38 and À107.78 at the PM3, AM1, MNDO and MINDO level of calculation, respectively [17].…”

“…Basis set 1 2 well as reported crystallographic [18,24,26,27] and semiempirical values [17]. In accordance with X-ray results, some of the predicted values are sensitive to the orientation adopted by the dihydrothiazine ring.…”

Multicomponent solid forms of antibiotic cephalexin towards improved chemical stability

“…Crystallization of CPX–PHB from MeOH–water (1 : 1) resulted in very fine needle crystals (fibre-like), which were difficult to mount in the goniometer of SCXRD as they were highly brittle in nature. The corresponding powder X-ray patterns were indexed with the fixed atomic coordinates taken from cephradine- p -hydroxybenzoic acid tetrahydrate (CCDC refcode VOQLIW) 36 using Rietveld refinement due to their partial similarity in XRD pattern. The lattice parameters of CPX–PHB hydrate and VOQLIW are very similar (Table 2).…”

“…aNote: the lattice parameters of VOQLIW are taken from ref. 36 and 3D coordinates of CPX–PHB hydrate are not available.…”

Supramolecular Self-Assembly Process during Gelation and Crystallization of Cefradine

“…Finally, the anisotropic crystal structures were formed, resulting in the layered stacking structure. In the structure of the DMF solvate (Figure e), the cefradine molecules are arranged end-to-end by the interaction of amino and carboxyl to form a supramolecular layer, and the layers are fixed by the interaction of solvent-cefradine and the carbonyl-amino, which perhaps indicates the mechanism of the self-assembly process.…”

Quantum mechanical calculations of the cephalosporin nucleus

“…The optimized orientations of the acetylamino group as expressed by the dihedral angle C8C7N20C21 for the S1-up conformer 3 correspond to the values of À155.198 3a and 26.248 3b, where the former is more stable by 7.82 kcal/mol. These orientations are in reasonably good agreement with previously reported crystallographic results: À156.798 for bis(cephradine)-2-acetonaphthone clathrate hydrate [30,31], À158.918 for bis(cefadroxil) 2,6-dihydroxynaphthalene clathrate nonahydrate [30], 30.638 for cephradine methyl 3-hydroxybenzoate clathrate [26] and 32.898 for cephradine bis(dimethylformamide) clathrate [26]. Previously reported semiempirical values for cephalotin are À145.48, À128.78, À160.38 and À107.78 at the PM3, AM1, MNDO and MINDO level of calculation, respectively [17].…”

“…Basis set 1 2 well as reported crystallographic [18,24,26,27] and semiempirical values [17]. In accordance with X-ray results, some of the predicted values are sensitive to the orientation adopted by the dihydrothiazine ring.…”

Multicomponent solid forms of antibiotic cephalexin towards improved chemical stability

“…Crystallization of CPX–PHB from MeOH–water (1 : 1) resulted in very fine needle crystals (fibre-like), which were difficult to mount in the goniometer of SCXRD as they were highly brittle in nature. The corresponding powder X-ray patterns were indexed with the fixed atomic coordinates taken from cephradine- p -hydroxybenzoic acid tetrahydrate (CCDC refcode VOQLIW) 36 using Rietveld refinement due to their partial similarity in XRD pattern. The lattice parameters of CPX–PHB hydrate and VOQLIW are very similar (Table 2).…”

“…aNote: the lattice parameters of VOQLIW are taken from ref. 36 and 3D coordinates of CPX–PHB hydrate are not available.…”

Supramolecular Self-Assembly Process during Gelation and Crystallization of Cefradine

“…Finally, the anisotropic crystal structures were formed, resulting in the layered stacking structure. In the structure of the DMF solvate (Figure e), the cefradine molecules are arranged end-to-end by the interaction of amino and carboxyl to form a supramolecular layer, and the layers are fixed by the interaction of solvent-cefradine and the carbonyl-amino, which perhaps indicates the mechanism of the self-assembly process.…”

Quantum mechanical calculations of the cephalosporin nucleus

“…The optimized orientations of the acetylamino group as expressed by the dihedral angle C8C7N20C21 for the S1-up conformer 3 correspond to the values of À155.198 3a and 26.248 3b, where the former is more stable by 7.82 kcal/mol. These orientations are in reasonably good agreement with previously reported crystallographic results: À156.798 for bis(cephradine)-2-acetonaphthone clathrate hydrate [30,31], À158.918 for bis(cefadroxil) 2,6-dihydroxynaphthalene clathrate nonahydrate [30], 30.638 for cephradine methyl 3-hydroxybenzoate clathrate [26] and 32.898 for cephradine bis(dimethylformamide) clathrate [26]. Previously reported semiempirical values for cephalotin are À145.48, À128.78, À160.38 and À107.78 at the PM3, AM1, MNDO and MINDO level of calculation, respectively [17].…”

“…Basis set 1 2 well as reported crystallographic [18,24,26,27] and semiempirical values [17]. In accordance with X-ray results, some of the predicted values are sensitive to the orientation adopted by the dihydrothiazine ring.…”

Multicomponent solid forms of antibiotic cephalexin towards improved chemical stability

“…Crystallization of CPX–PHB from MeOH–water (1 : 1) resulted in very fine needle crystals (fibre-like), which were difficult to mount in the goniometer of SCXRD as they were highly brittle in nature. The corresponding powder X-ray patterns were indexed with the fixed atomic coordinates taken from cephradine- p -hydroxybenzoic acid tetrahydrate (CCDC refcode VOQLIW) 36 using Rietveld refinement due to their partial similarity in XRD pattern. The lattice parameters of CPX–PHB hydrate and VOQLIW are very similar (Table 2).…”

“…aNote: the lattice parameters of VOQLIW are taken from ref. 36 and 3D coordinates of CPX–PHB hydrate are not available.…”

Supramolecular Self-Assembly Process during Gelation and Crystallization of Cefradine

“…Finally, the anisotropic crystal structures were formed, resulting in the layered stacking structure. In the structure of the DMF solvate (Figure e), the cefradine molecules are arranged end-to-end by the interaction of amino and carboxyl to form a supramolecular layer, and the layers are fixed by the interaction of solvent-cefradine and the carbonyl-amino, which perhaps indicates the mechanism of the self-assembly process.…”