Synthesis, structure, and stereospecific cross-[2+2] photocycloaddition of pseudodimeric complexes based on ammonioalkyl derivatives of styryl dyes

2016 ◽  
Vol 40 (9) ◽  
pp. 7542-7556 ◽  
Author(s):  
Sergey P. Gromov ◽  
Artem I. Vedernikov ◽  
Sergey K. Sazonov ◽  
Lyudmila G. Kuz’mina ◽  
Natalia A. Lobova ◽  
...  

Two different styryl dyes form pseudodimeric complexes via hydrogen bonding and stacking interactions; irradiation of these complexes gives rctt-cyclobutane derivatives.

2007 ◽  
Vol 9 (4) ◽  
pp. 497-509 ◽  
Author(s):  
Lesley R. Rutledge ◽  
Craig A. Wheaton ◽  
Stacey D. Wetmore

2006 ◽  
Vol 62 (4) ◽  
pp. o1319-o1320 ◽  
Author(s):  
Min-Hui Cao ◽  
Sheng-Zhen Xu ◽  
Yang-Gen Hu

The title compound, C15H16N2O2S, contains a five-membered thiophene ring fused to a benzene ring and a substituted pyrimidinone ring. All three rings in each of the independent molecules of the asymmetric unit lie in approximately the same plane. The crystal structure is stabilized by intermolecular C—H...O hydrogen bonding and π–π stacking interactions.


2006 ◽  
Vol 62 (1) ◽  
pp. 165-165
Author(s):  
M. Luz Godino Salido ◽  
Paloma Arranz Mascarós ◽  
Rafaél López Garzón ◽  
M. Dolores Gutiérrez Valero ◽  
John N. Low ◽  
...  

Some of the data collection details for compound (VIII) were incorrectly given in Table 1 of Godino Salido et al. (2004). The data for compound VIII in this paper were collected using synchrotron radiation at the Daresbury SRS station 9.8, λ = 0.6935 Å (Cernik et al., 1997; Clegg, 2000). The data were collected using a Bruker SMART 1K CCD diffractometer using ω rotation with narrow frames. The computer program used in the data collection was SMART (Bruker, 2001) and for cell refinement and data reduction SAINT (Bruker, 2001).


1976 ◽  
Vol 54 (14) ◽  
pp. 2228-2230 ◽  
Author(s):  
Ted Schaefer ◽  
J. Brian Rowbotham

The conformational preferences in CCl4 solution at 32 °C of the hydroxyl groups in bromine derivatives of 1,3-dihydroxybenzene are deduced from the long-range spin–spin coupling constants between hydroxyl protons and ring protons over five bonds. Two hydroxyl groups hydrogen bond to the same bromine substituent in 2-bromo-1,3-dihydroxybenzene but prefer to hydrogen bond to different bromine substituents when available, as in 2,4-dibromo-1,3-dihydroxybenzene. When the OH groups can each choose between two ortho bromine atoms, as in 2,4,6-tribromoresorcinol, they apparently do so in a very nearly statistical manner except that they avoid hydrogen bonding to the common bromine atom.


1972 ◽  
Vol 27 (6) ◽  
pp. 663-674 ◽  
Author(s):  
Gotthard H. Krause ◽  
Herbert Hoyer

The change of free enthalpy involved in intramolecular hydrogen bonding is smaller if the proton acceptor group can rotate round a single bond, as compared to proton acceptor groups which are fixed in a position optimal for hydrogen bonding. Also, the free enthalpy change is altered when the rotation of the proton acceptor is sterically restricted. This is demonstrated by comparing the absorptions of carbonyl stretching vibrations in the infrared spectra of certain compounds showing rotational isomerism. In the present study derivatives of 5-hydroxy-2,2-dimethyl-6-carbomethoxychromanone- (4), 3-nitrosalicylaldehyde and 3-nitro-2-hydroxy-acetophenones substituted in the position 5 and 6 are examined.


2019 ◽  
Vol 8 (2S11) ◽  
pp. 3182-3190

Chemical speciation of ternary complexes of L-arginine and L-aspartic acid with essential transition metal ions was studied pH metrically. The following MLX, MLXH and ML2X ternary species are detected and reported in this paper. The existence of different ternary species is established from modeling studies using the computer program MINIQUAD75. The relative concentrations (M: L: X=1:2:2, 1:2:4, 1:4:2) and stabilities of the ternary species are compared with those of binary species. The extra stability associated with the ternary complexes is attributed to factors such as charge neutralization, chelate effect, stacking interactions and hydrogen bonding. Trend in variation of stability constants with the change in the mole fraction of the surfactant in various micellar media is explained on the basis of electrostatic and non-electrostatic forces. Distribution diagrams in relation to pH and plausible structures were presented.


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