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71.
Suchada Chantrapromma Anwar Usman Hoong‐Kun Fun 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(11):m531-m533
In the title compound [systematic name: triaqua(1,4,7,10,13,16‐hexaoxacyclooctadecane‐κ6O)(2‐nitrophenolato‐κO)barium(II)–aqua(1,4,7,10,13,16‐hexaoxacyclooctadecane‐κ6O)‐ bis(2‐nitrophenolato‐κ2O,O′)barium(II)–2‐nitrophenolate (1/1/1)], [Ba(C12H24O6)(C6H4NO3)(H2O)3][Ba(C12H24O6)(C6H4NO3)2(H2O)](C6H4NO3), the two BaII atoms encapsulated by the 18‐crown‐6 rings have different coordinations. Although both BaII atoms are coordinated to the six O atoms of the crowns, in the neutral moiety, the BaII atom is coordinated to one terminal O atom from a water molecule, two phenolate O atoms and two nitro‐group O atoms, while in the cationic moiety, the BaII atom is coordinated to three terminal O atoms from water molecules and one phenolate O atom. Both the crowns are eclipsed and translated along the b direction. In the asymmetric unit, the three components are interconnected by four O—H?O interactions. The packing is stabilized by two intermolecular C—H?O interactions and by one O—H?O interaction. 相似文献
72.
Tetrahydrocarbazol‐4‐one represents a prevalent framework of numerous natural products and pharmaceuticals. This review summaries the recent synthetic progresses of this core structure, including Fischer indolization, oxidative and reductive coupling, α‐arylative cyclization by means of transition‐ metal catalysis or under metal‐free conditions, and other methods. The recently emerged enantioselective catalytic methods of tetrahydrocarbazol‐4‐ ones are also described. The mechanistic insights and applications of these strategies as a key step in the total (formal) synthesis of complex alkaloids are highlighted as well. 相似文献
73.
Anwar Usman Ibrahim Abdul Razak Hoong‐Kun Fun Suchada Chantrapromma Yan Zhang Jian‐Hua Xu 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):o59-o62
In the syn‐ and anticlinal isomers of the title compound, C22H18N2O6, the indole moiety is not completely planar, with the pyrrolidine ring being distorted very slightly towards a conformation intermediate between half‐chair and envelope. The molecular and packing structures in the crystals of these isomers are stabilized by C—H?O interactions. 相似文献
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75.
Muhammad Rafiq Muhammad Khalid Muhammad Nawaz Tahir Muhammad Umair Ahmad Muhammad Usman Khan Muhammad Moazzam Naseer Ataualpa Albert Carmo Braga Shabbir Muhammad Zahid Shafiq 《应用有机金属化学》2019,33(11)
Present study advocates the joint experimental and computational studies of two potent benzoimidazole‐based hydrazones with chemical formula C23H18F2N4O ( 5a ) and C25H22FN5O3 ( 5b ). Both 5a and 5b were synthesized and resolved into their crystal structures using SC‐XRD for the assessment of bond lengths, bond angles, unit cells and space groups. The structures of 5a and 5b were chemically characterized using infrared (FT‐IR), UV–Visible, nuclear magnetic resonance (1H‐NMR and 13C‐NMR), EIMS and elemental analysis. DFT at M06‐2X/6‐31G(d,p) level of theory was performed to get optimized structures and countercheck the experimental findings. Overall, DFT findings show excellent concurrence with the experimental data which confirms the purity of both compounds. FMO, NBO analysis, MEP surfaces and nonlinear optical (NLO) properties were explored at same level of theory. UV–Vis analysis at TDDFT/M06‐2X/6‐31G(d,p) level of theory showed that 5b is red shifted with λmax 331.69 nm as compared to 5a with λmax 240.25 nm. Global reactivity parameters were estimated using energy of FMOs indicated the greater harness value than the softness values of 5a and 5b . NBO analysis confirmed that the presence of non‐covalent interactions, hydrogen bonding and hyper conjugative interactions are pivotal cause for the existence of 5a and 5b in the solid‐state. NLO results of 5a and 5b were observed better than standard molecule recommended the NLO activity of said molecules for optoelectronic applications. 相似文献
76.
Anwar Usman Ibrahim Abdul Razak Suchada Chantrapromma Sujit K. Ghorai Dipakranjan Mal Hoong‐Kun Fun Gur Dayal Nigam 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1118-1119
The title compound, C19H16O, crystallizes with two molecules of opposite chirality in the asymmetric unit. In both molecules, the naphthalene and cyclopentanone moieties are individually planar. The two cyclopentane rings adopt envelope conformations, while the cyclohexane ring adopts a boat conformation. 相似文献
77.
Usman Mohammad Smith Mark D. zur Loye Hans-Conrad 《Journal of chemical crystallography》2021,51(3):451-456
Journal of Chemical Crystallography - Deep blue, prism-shaped, X-ray diffraction quality single crystals of a new quaternary rubidium cobalt germanate, exact composition Rb2Co1.85Ge1.15O6, were... 相似文献
78.
79.
Muhammad Ramzan Saeed Ashraf Janjua Muhammad Haroon Riaz Hussain Muhammad Usman Muhammad Usman Khan Waqas Amber Gill 《International journal of quantum chemistry》2022,122(1):e26821
Organic photovoltaic solar cells are being designed to offer a low energy photovoltaic (PV) solution. Optimizing the molecular backbone is one the most important technique for improving the photovoltaic characteristic of A-D-A type small active layer molecules. Herein, we have designed and theoretical characterized six new molecules by end-capped and bridging core modifications of recently synthesized molecule BFHIC-4F. Enhancement in photovoltaic, optoelectronic and physio-chemical properties of newly designed molecules are seen by doing such modifications. Different advanced quantum chemical techniques have been employed to evaluate the performance of newly planned molecules. Large open circuit voltage and narrow band gap suggested that the designed molecules are efficient aspirants for solar cell applications. Moreover, maximum absorption capability in near-infra-red (NIR) region is observed for these newly designed molecules. To sum up, outcomes of all analyses advocated that the designed molecules are efficient candidates for solar cell applications. 相似文献
80.