Hydrogen Atom and Hydride Transfer in the Reactions of Chromium(IV) and Chromium(V) Complexes with Rhodium Hydrides. Crystal Structure of a Superoxorhodium(III) Product

2000 ◽  
Vol 39 (4) ◽  
pp. 736-740 ◽  
Author(s):  
Andreja Bakac ◽  
Ilia A. Guzei
Keyword(s):  
Crystal Structure ◽  
Hydrogen Atom ◽  
Hydride Transfer ◽  
Rhodium Hydrides

Crystal structure of tamsulosin hydrochloride, C20H29N2O5SCl

2021 ◽  
pp. 1-7
Author(s):  
Nilan V. Patel ◽  
Joseph T. Golab ◽  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Atom ◽  
Powder Diffraction ◽  
Density Functional ◽  
Carbon Chain ◽  
Strong Hydrogen Bond ◽  
Powder Diffraction File ◽  
Ether Oxygen ◽  
Sulfonamide Group

The crystal structure of tamsulosin hydrochloride has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Tamsulosin hydrochloride crystallizes in space group P21 (#4) with a = 7.62988(2), b = 9.27652(2), c = 31.84996(12) Å, β = 93.2221(2)°, V = 2250.734(7) Å3, and Z = 4. In the crystal structure, two arene rings are connected by a carbon chain oriented roughly parallel to the c-axis. The crystal structure is characterized by two slabs of tamsulosin hydrochloride molecules perpendicular to the c-axis. As expected, each of the hydrogens on the protonated nitrogen atoms makes a strong hydrogen bond to one of the chloride anions. The result is to link the cations and anions into columns along the b-axis. One hydrogen atom of each sulfonamide group also makes a hydrogen bond to a chloride anion. The other hydrogen atom of each sulfonamide group forms bifurcated hydrogen bonds to two ether oxygen atoms. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1415.

scholarly journals Crystal Structure of the FAD-Containing Ferredoxin-NADP+Reductase from the Plant PathogenXanthomonas axonopodispv. citri

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
María Laura Tondo ◽  
Ramon Hurtado-Guerrero ◽  
Eduardo A. Ceccarelli ◽  
Milagros Medina ◽  
Elena G. Orellano ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Transfer Process ◽  
Plant Pathogen ◽  
Active Site ◽  
Functional Divergence ◽  
Hydride Transfer ◽  
Citrus Canker ◽  
Xanthomonas Axonopodis ◽  
C Terminus

We have solved the structure of ferredoxin-NADP(H) reductase, FPR, from the plant pathogenXanthomonas axonopodispv. citri, responsible for citrus canker, at a resolution of 1.5 Å. This structure reveals differences in the mobility of specific loops when compared to other FPRs, probably unrelated to the hydride transfer process, which contributes to explaining the structural and functional divergence between the subclass I FPRs. Interactions of the C-terminus of the enzyme with the phosphoadenosine of the cofactor FAD limit its mobility, thus affecting the entrance of nicotinamide into the active site. This structure opens the possibility of rationally designing drugs against theX. axonopodispv. citri phytopathogen.

Understanding Hydrogen Atom and Hydride Transfer Processes during Electrochemical Alcohol and Aldehyde Oxidation

ACS Catalysis ◽  
2021 ◽  
pp. 15110-15124
Author(s):  
Michael T. Bender ◽  
Robert E. Warburton ◽  
Sharon Hammes-Schiffer ◽  
Kyoung-Shin Choi
Keyword(s):  
Hydrogen Atom ◽  
Hydride Transfer ◽  
Transfer Processes ◽  
Aldehyde Oxidation

Structure of 5,5-dimethyl-2-phenylimino-Δ3-1,3,4-thiadiazoline from oxidative cyclization of a thiosemicarbazone

1987 ◽  
Vol 65 (6) ◽  
pp. 1154-1157 ◽  
Author(s):  
R. Faggiani ◽  
M. Kaminski ◽  
C. J. L. Lock ◽  
J. Warkentin
Keyword(s):  
Crystal Structure ◽  
Hydrogen Atom ◽  
Phenyl Ring ◽  
Direct Methods ◽  
Oxidative Cyclization ◽  
Repulsive Interaction ◽  
Sulphur Atom ◽  
Normal Range ◽  
X Ray ◽  
Bond Lengths

The X-ray crystal structure of 5,5-dimethyl-2-phenylimino-Δ3-1,3,4-thiadiazoline, C10H11N3S, has been determined. The compound is monoclinic, P21/c (No. 14), with a = 13.200(5), b = 6.340(4), and c = 13.823(4) Å, β = 113.50(4)°, and Z = 4. The structure was determined by direct methods and refined to R = 0.061, Rw = 0.067 for 1277 unique reflections. The molecule has the Z configuration. The thiadiazoline ring is planar. C—N and N=N bond lengths are within the normal range. The C—S bond lengths are similar to those we have observed previously in thiazolidines. Angles differ markedly from an expected average 108°. The small C—S—C angle (90.6(2)°) is accompanied by larger C—N=N angles (114.9(3), 117.8(3)°). The phenyl ring is not coplanar with the thiadiazoline ring (dihedral angle 38.6(4)°) because of repulsive interaction of the phenyl o-hydrogen atom with the sulphur atom.

scholarly journals Hydrogen bonding structure and polymorphism in agrochemicals

2014 ◽  
Vol 70 (a1) ◽  
pp. C540-C540
Author(s):  
Antonietta Di Pumpo ◽  
Mark Weller ◽  
Sax Mason ◽  
Marie-Hélène Lemée-Cailleau
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Atom ◽  
Hydrogen Bonds ◽  
Physical Properties ◽  
Crystallization Process ◽  
Spatial Arrangement ◽  
Crystal Habit ◽  
Bonding Structure ◽  
Significant Toxicity

Polymorphism of crystals, crystal habit and crystal growth are important factors that must be controlled for any commercial crystallization process. Pharmaceuticals and agrochemicals are two of the most industrially-important, active-molecule systems for which the physical properties are strongly correlated to their crystal structure. While pharmaceuticals have attracted more academic interest to date, the market for agrochemicals is also very considerable, amounting to $15 bn annually. Given the potential significant toxicity of some agrochemicals, the ability to control physical properties such as solubility and dissolution rates, which depend on the crystal structure of the agrochemical itself, represents a way of optimizing the ratio between the amount of product used and its efficiency, improving its function and reducing its environmental impact. Hydrogen bonds play a crucial role in the spatial arrangement of the active molecules and the crystallization process. However, high accuracy and precision of the hydrogen atom positions can only be achieved through single crystal neutron diffraction (SND). SND experiments have been performed on three herbicides - isoproturon (IPU), pendimethalin (PDM), and diflufenican (DFF) - and the fungicide cyprodinil (CYP) [1][2]. All four structure refinements show a ten-time improvement in precision in the hydrogen atom positions compared to SXD with accurately determined nuclear positions. For cyprodinil, which crystallises as two polymorphs, A and B, differences in the hydrogen bonding network have been determined. Form A is governed by single, linear hydrogen bonds between two molecules, while the B form is characterized by the presence of dimers linked through pairs of hydrogen bonds, leading to a stable 8-membered ring. These differences in structure are reflected in the physical properties of the two polymorphs such as melting point and the observed slow inter-conversion that takes place during storage.

scholarly journals Syntheses of tetrahydroquinoline-based chiral carbene precursors and the related chiral NHC–Au(i) complex

RSC Advances ◽  
2020 ◽  
Vol 10 (58) ◽  
pp. 35253-35256
Author(s):  
Licheng Zhan ◽  
Gengtao Zhang ◽  
Jiwei Wang ◽  
Jun Zhang
Keyword(s):  
Crystal Structure ◽  
Hydrogen Atom ◽  
Gold Complex ◽  
Facile Synthesis

The facile synthesis of tetrahydroquinoline-based chiral carbene precursors is reported. A rare Au⋯H–C(sp3) interaction between Au(i) and the hydrogen atom was observed in the crystal structure of a related NHC–gold complex.

The crystal structure of Görgeyite K2SO4 · 5 CaSO4 H2O

1980 ◽  
Vol 151 (1-2) ◽  
Author(s):  
G. W. Smith ◽  
R. Walls
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Atom ◽  
Water Molecule ◽  
Potassium Atom ◽  
Calcium Atom ◽  
Oxygen Coordination ◽  
Oxygen Atoms

AbstractThe crystal structure of the mineral görgeyite, KTwo independent calcium atoms, one of which sits on the diad axis, are nine-fold coordinated by oxygen atoms in a closely similar arrangement, with average Ca–O distances of 2.52 Å in the range 2.40–2.68 Å. A third calcium atom is eight-fold coordinated with a mean Ca–O distance of 2.46 Å in a range of 2.37–2.64 Å.The potassium atom is also eight-fold coordinated. The three independent sulphate ions are approximately regular with mean S–O distances of 1.472(8), 1.477(27), and 1.470(7) Å respectively but their behaviour in providing oxygen coordination is different for each. The hydrogen atom of the water molecule has not been positively located though it is likely that a hydrogen bond is present.

Acid-promoted hydride transfer from an NADH analogue to a Cr(iii)–superoxo complex via a proton-coupled hydrogen atom transfer

2021 ◽  
Author(s):  
Tarali Devi ◽  
Yong-Min Lee ◽  
Shunichi Fukuzumi ◽  
Wonwoo Nam
Keyword(s):  
Hydrogen Atom ◽  
Radical Cation ◽  
Hydride Transfer ◽  
Hydrogen Atom Transfer ◽  
Atom Transfer ◽  
Acid Proceeds

Acid-promoted hydride transfer from an NADH analogue to a Cr(iii)–superoxo complex in the presence of acid proceeds via the full formation of the NADH analogue radical cation, followed by the decay of the radical, and accompanied then by the formation of NAD+.

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