نتایج جستجو برای: urea bond
تعداد نتایج: 107315 فیلتر نتایج به سال:
The structure of the title compound, C(14)H(9)Cl(3)N(2)OS, is composed of discrete mol-ecules with bond lengths and angles quite typical for thio-urea compounds of this class. The plane containing the thio-carbonyl and carbonyl groups subtends dihedral angles of 48.19 (3) and 87.51 (3)° with the planes formed by the 3-chloro and 2,6-dichloro-phenyl rings, respectively; the dihedral angle betwee...
We report on the crystal structure of urea (U) with acetic acid (A), its physical stability and its predictability using computational methods. The crystal structure of urea:acetic acid (U:A) shows hydrogen-bond ribbons and a 1:2 stoichiometry. Crystal structure prediction calculations are presented for two sets of U:A stoichiometries: 1:1 and 1:2. A 1:3 stoichiometry is also partially explored...
An algorithm is proposed for the structural optimization of periodic systems in internal (chemical) coordinates. Internal coordinates may include in addition to the usual bond lengths, bond angles, out-of-plane and dihedral angles, various "lattice internal coordinates" such as cell edge lengths, cell angles, cell volume, etc. The coordinate transformations between Cartesian (or fractional) and...
The selectivity of acetylcholine (A-Ch)-activated channels for alkali cations, organic cations, and nonelectrolytes in cultured muscle cells has been studied. To test the effect of size, charge, and hydrogen-binding capacity of permeant molecules on their permeability, we have obtained the selectivity sequences of alkali cations, compared the permeability of pairs of permeant molecules with sim...
1N-methyl-1S-methyl-2-nitroethylene (NMSM) is an important intermediate in the synthesis of anti-ulcer drug Ranitidine. NMSM is a push pull alkene equivalent to glycine possessing both electron-donating and withdrawing nitro group at both ends of olefinic bond. The solid phase FT-IR and FT-Raman spectra of NMSM have been recorded in the region 4000-400cm and 3500-100cm, respectively. The molecu...
In the title compound, C(20)H(21)N(5)O, the conformation about the imine bond [1.289 (3) Å] is E. Overall, the mol-ecule is disk-shaped with the imidazole ring located above the remainder of the mol-ecule and with the dihedral angles of 10.97 (15) and 12.11 (15)°, respectively, between the imidazole ring and the phenyl and methyl-benzene rings; the dihedral angle between the aromatic rings is 8...
In the title compound, C(21)H(23)N(5)O(2), the conformation about the imine bond [1.287 (3) Å] is E. Overall, the mol-ecule has a disk shape, the dihedral angles between the imidazole ring and the meth-oxy-phenyl and methyl-phenyl rings being 49.42 (13) and 42.62 (13)°, respectively; the dihedral angle between the benzene rings is 20.11 (11)°. In the urea moiety, the N-H atoms are anti to each ...
In the title thio-urea derivative, C(16)H(17)N(3)OS, the hy-droxy- and methyl-substituted benzene rings form dihedral angles of 9.62 (12) and 55.69 (6)°, respectively, with the central CN(3)S chromophore (r.m.s. deviation = 0.0117 Å). An intra-molecular O-H⋯N hydrogen bond ensures the coplanarity of the central atoms. The H atoms of the NH groups are syn and the conformation about the N=C doubl...
The title compound, [(1-{4-[2-(2,4-di-hydroxy-phen-yl)diazen-1-yl]phen-yl}ethyl-idene)amino]-thio-urea, 1,1,2,2-tetra-chloro-ethane monosolvate, C15H15N5O2S·C2H2Cl4, was prepared from 4-(4-acetyl-phenyl-diazendi-yl)resorcinol and thio-semicarbazide and recrystallized from mixed solvents of tetra-chloro-ethane and n-hexane. 1H NMR and X-ray diffraction data are in support of the thione tautomeri...
The electronic and steric effects as well as hydrogen bonds on the formation of the heteroligand complexes between monodentate amino acid based phosphoramidite and monodentate phosphine ligands were studied. Pure heterocomplex formation through the hydrogen bond between LEUPhos and a urea based phosphine is observed leading to highly active and selective catalyst. Substrate orientation through ...
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