نتایج جستجو برای: urea bond
تعداد نتایج: 107315 فیلتر نتایج به سال:
In the title compound, C(15)H(9)F(4)N(3)O(2)S, the N,N'-disubstituted thio-urea fragment adopts a cis,trans geometry, stabilized by an intra-molecular N-H⋯O hydrogen bond to the carbonyl O atom of the tetra-fluoro-benzoyl group. The central thio-urea group makes dihedral angles of 47.79 (7) and 35.54 (8)° with the two aromatic rings. In the crystal, mol-ecules are linked via N-H⋯O and N-H⋯S hyd...
In the title compound, C(12)H(12)ClF(3)N(2)OS, the dihedral angle between the benzene ring and the thio-urea fragment is 69.41 (5)°. The thio-urea N-H atoms adopt an anti conformation, such that one of them forms an intra-molecular N-H⋯O hydrogen bond, generating an S(6) ring. In the crystal, both N-H groups form inversion dimers, one via a pair of N-H⋯S hydrogen bonds and one via a pair of N-H...
The asymmetric unit of the binuclear title compound, [Sn(2)(C(2)O(4))(C(6)H(5))(6)(CH(4)N(2)S)(2)], consists of one half of the organotin(IV) mol-ecule. The remainder is generated by a twofold rotation axis passing through the mid-point of the oxalate C-C bond. The Sn(IV) atom exhibits a distorted trigonal-bipyramidal coordination environment with the phenyl groups in equatorial positions and t...
In the title complex, [Hg(NCS)2(CH4N2S)2], the Hg(II) atom is four-coordinated having an irregular four-coordinate geometry composed of four thione S atoms of two thio-cyanate groups and two thio-urea groups. The S-Hg-S angles are 172.02 (9)° for the trans-thio-cyanate S atoms and 90.14 (5)° for the cis-thio-urea S atoms. The mol-ecular structure is stabilized by an intra-molecular N-H⋯S hydrog...
A previous study of synthesizing low mole ratio urea–formaldehyde (UF) and urea–melamine–formaldehyde (UMF) resins, which included an acidic reaction step at the beginning of the typical resin synthesis procedure to obtain higher uron-type methylene–ether group contents, was repeated with the acidic reaction step extended to a higher viscosity. Compared to previous resins, the synthesized resin...
The title compound, C(13)H(9)F(3)N(2)O(2)S, crystallizes with two independent mol-ecules in the asymmetric unit. The central thio-urea core is roughly coplanar with the furan and benzene rings, showing O-C-N-C(S) torsion angles of 2.3 (4) and -11.4 (2)° and (S)C-N-C-C torsion angles of -2.4 (4) and -28.8 (4)°, respectively, in the two independent mol-ecules. The trans-cis geometry of the thio-u...
The title compound, C(4)H(6)N(3)OS(+)·H(2)PO(4) (-), (I), was obtained as a result of hydrolysis of [(1,3-thia-zol-2-yl-amino)-carbon-yl]-phospho-ramidic acid, (II), in water. X-ray analysis has shown that the N-P bond in (II) breaks, leading to the formation of the substituted carbamide (I). This compound exists as an inter-nal salt. The unit cell consists of a urea cation and an anion of H(2)...
Sulfhydryl groups of ovalbumin were chemically modified under denaturing conditions in the absence and presence of dithiothreitol, and effects on the secondary structure of the protein were investigated by circular dichroic (CD) measurements. The contents of alpha-helix, beta-structure, and "random coil" (unordered, nonrepetitive structure) were estimated by simulation of the CD spectra and usi...
Haloalkane dehalogenase (DhlA) was used as a model protein to explore the possibility to use molecular dynamics (MD) simulations as a tool to identify flexible regions in proteins that can serve as a target for stability enhancement by introduction of a disulfide bond. DhlA consists of two domains: an alpha/beta-hydrolase fold main domain and a cap domain composed of five alpha-helices. MD simu...
Supramolecular gels are topical soft materials involving the reversible formation of fibrous aggregates using non-covalent interactions. There is significant interest in controlling the properties of such materials by the formation of multicomponent systems, which exhibit non-additive properties emerging from interaction of the components. The use of hydrogen bonding to assemble supramolecular ...
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