scholarly journals Preparation and Structure of Novel Chiral 4,6-Disubstituted Tetrahydropyrimidinones

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
David Frain ◽  
Fiona Kirby ◽  
Patrick McArdle ◽  
Patrick O'Leary
Keyword(s):  
Crystal Growth ◽  
Initial Study ◽  
Hiv Protease ◽  
Synthetic Route ◽  
Hydrogen Bonded

The synthesis of a number of novel 4,6-disubstituted tetrahydropyrimidinones is described. The synthetic route described is applied to the synthesis of two stereoisomers. The structure of one tetrahydropyrimidinone was determined by XRD and showed an interesting hydrogen-bonded ribbon in the direction of crystal growth. These pyrimidinones are members of a class of compounds with diverse bioactivity. An initial study of their activity versus HIV protease is included.

Hydrogen bonded nonlinear optical γ-glycine: Crystal growth and characterization

2005 ◽  
Vol 280 (3-4) ◽  
pp. 581-586 ◽  
Author(s):  
B. Narayana Moolya ◽  
A. Jayarama ◽  
M.R. Sureshkumar ◽  
S.M. Dharmaprakash
Keyword(s):  
Crystal Growth ◽  
Nonlinear Optical ◽  
Hydrogen Bonded

A Novel Route to 2-Arylquinolines: Reductive Cleavage of 2′-Nitroaryl-∆2-isoxazolines

Synlett ◽  
2017 ◽  
Vol 28 (11) ◽  
pp. 1341-1345 ◽  
Author(s):  
Mukul Lal ◽  
Prashantha Kamath ◽  
Russell Viner ◽  
Stephen Smith
Keyword(s):  
Hydrogen Bond ◽  
Dft Calculations ◽  
Reductive Cleavage ◽  
Reductive Cyclization ◽  
Synthetic Route ◽  
Metal Free ◽  
Reaction Proceeds ◽  
Hydrogen Bonded

A novel synthetic route for the synthesis of quinolines starting from Δ2-isoxazolines under reductive conditions is reported. The ­reductive cyclization to quinolines is achieved under both metal and metal-free conditions. The reaction proceeds via an intramolecular N–H···O hydrogen bond intermediate, accelerating the reductive cleavage 1000-fold (DFT calculations) in comparison with non-hydrogen bonded system.

Wechselwirkungen in Molekülkristallen, 174 [1, 2]. Kristallzüchtung und Strukturbestimmung verschiedenartig Methyl-substituierter Imidodiphosphorsäuretetraphenylester / Interaction in Molecular Crystals, 174 [1, 2]. Crystal Growth and Structure Determination of Differently Methyl-Substituted Tetraphenyl Imidodiphosphates

2001 ◽  
Vol 56 (6) ◽  
pp. 469-482 ◽  
Author(s):  
Hans Bock ◽  
Erik Heigel
Keyword(s):  
Crystal Growth ◽  
Structure Determination ◽  
Molecular Crystals ◽  
Structural Data ◽  
Structural Motif ◽  
Cesium Salts ◽  
Hydrogen Bonded

Abstract Four differently methyl-substituted tetraphenyl imidodiphosphates [(H3C)nC6H5-n]2PO-NH-PO[C6H5-n(C3)n] (n = 1, 2), i. e. the 4-, 3,4-, 3,5-and 2,3-derivatives, have been crystallized and their structures determined to gain information on the spatial requirements as ligands in the corresponding cesium salts. According to the packing coefficients calculated from the structural data, they increase in the sequence 4<3,5<3,4<2,3. The most perturbed structural motif is the hydrogen bonded, eight-membered of each the dimer subunits.

scholarly journals Concerning the selection of crystallization modifiers for non- hydrogen bonded systems: the case of benzophenone.

CrystEngComm ◽  
2021 ◽  
Author(s):  
Roger J Davey ◽  
Simon N Black ◽  
Adrian Hutchinson
Keyword(s):  
Crystal Growth ◽  
Intermolecular Interaction ◽  
Design Strategy ◽  
Polar Crystals ◽  
Hydrogen Bonded Systems ◽  
Selection Of ◽  
Hydrogen Bonded

A design strategy for the selection of crystal growth modifiers for non-polar crystals is proposed and its application demonstrated for the case of benzophenone. The strongest intermolecular interaction in the...

Montmorillonite Dendrites

1974 ◽  
Vol 32 ◽  
pp. 454-455
Author(s):  
Necip Güven ◽  
Rodney W. Pease
Keyword(s):  
Crystal Growth ◽  
Growth Mechanism ◽  
Growth Front ◽  
Morphological Features ◽  
Dendritic Crystal ◽  
Crystal Growth Mechanism

Morphological features of montmorillonite aggregates in a large number of samples suggest that they may be formed by a dendritic crystal growth mechanism (i.e., tree-like growth by branching of a growth front).

TEM and cathodoluminescence of precipitates in II-VI semiconductors

1988 ◽  
Vol 46 ◽  
pp. 488-489
Author(s):  
Joanna L. Batstone
Keyword(s):  
Crystal Growth ◽  
Band Gap ◽  
Local Strain ◽  
Wide Band ◽  
Optoelectronic Device ◽  
Wide Band Gap ◽  
Bulk Crystal Growth ◽  
Transmission Electron ◽  
Device Applications ◽  
Stoichiometry Control

Interest in II-VI semiconductors centres around optoelectronic device applications. The wide band gap II-VI semiconductors such as ZnS, ZnSe and ZnTe have been used in lasers and electroluminescent displays yielding room temperature blue luminescence. The narrow gap II-VI semiconductors such as CdTe and HgxCd1-x Te are currently used for infrared detectors, where the band gap can be varied continuously by changing the alloy composition x.Two major sources of precipitation can be identified in II-VI materials; (i) dopant introduction leading to local variations in concentration and subsequent precipitation and (ii) Te precipitation in ZnTe, CdTe and HgCdTe due to native point defects which arise from problems associated with stoichiometry control during crystal growth. Precipitation is observed in both bulk crystal growth and epitaxial growth and is frequently associated with segregation and precipitation at dislocations and grain boundaries. Precipitation has been observed using transmission electron microscopy (TEM) which is sensitive to local strain fields around inclusions.

STM studies of crystal growth

1991 ◽  
Vol 49 ◽  
pp. 374-375
Author(s):  
M. G. Lagally
Keyword(s):  
Crystal Growth ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Sputter Deposition ◽  
Field Of View ◽  
Scanning Tunneling ◽  
Wide Field ◽  
Tunneling Microscopy ◽  
Wide Field Of View ◽  
The One

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.

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