In the present work, in order to investigate the electronic excited-state intermolecular hydrogen bonding between the chromophore coumarin 153 (C153) and the room-temperature ionic liquid N,N-dimethylethanolammonium formate (DAF), both the geometric structures and the infrared spectra of the hydrogen-bonded complex C153-DAF(+) in the excited state were studied by a time-dependent density functi...

the formation constants of the species formed in the systems fr + glycine + dioxovanadium(v) + and h+ + glycine have been determined in aqueous solutions of methanol at 25 °c and constant ionicstrength, using spectrophotometric and potentiometric techniques. it was shown thatdioxovanadium(v) forms two mononuclear 1 : land 1:2 complexes with glycine. the formationconstants in various media were ...

[structure; see text] An iterative synthetic route to organic-soluble ureido-naphthyridine oligomers has been developed. Use of this protocol allowed synthesis of a short ureido-naphthyridine oligomer, which presents a self-complementary DDAADDAA hydrogen bonding array (D = hydrogen bond donor, A = hydrogen bond acceptor). Strong self-association via eight hydrogen bonds was observed in organic...

Hydrogen bonding heavily influences conformations, rate of reactions, and chemical equilibria. The development of a method to monitor hydrogen bonding interactions independent of polarity is challenging as both are linked. We have developed two solvatochromic dyes that detect hydrogen-bond-donating solvents. The unique solvatochromism of the triazine architecture has allowed the development of ...

introduction : the aim of this in vitro study was to evaluate the effect of smear layer on the push-out bond strength of white mineral trioxide aggregate (wmta) with and without disodium hydrogen phosphate (na 2 hpo 4 ). materials and methods: dentin discs with standard cavities were obtained from extracted human single-rooted teeth and divided to 4 groups ( n =15) according to the irrigation r...

Widespread arguments of the hydrogen bond are criticized with respect to theories of protein folding and interactions of proteins with their specific ligands. Contrary to popular belief, by no means does the hydrogen bond play an important role in determining the conformation of proteins and the interactions of proteins with specific substrates. Stereotypical thinking on the hydrogen bond const...

Two mol-ecules of the title compound, C(15)H(13)N(3)O(3)S, are linked by an inter-molecular N-H⋯S hydrogen bond. There is also an intra-molecular N-H⋯O hydrogen bond, forming a six-membered ring. The steric restriction of the m-methyl and p-nitro groups, as well as the intra-molecular hydrogen bond, are the main factors influencing the mol-ecular conformation.

The title compound, C11H13NO6, exhibits an intra-molecular O-H⋯O=C hydrogen bond between the N-hydroxyl H atom and carbonyl O atom of the neighboring acetyl group. This finding contradicts a previously published model in which the hydrogen bond was postulated to occur with the neighboring carbomethoxy group. This relatively strong hydrogen bond [O-H⋯O: D = 2.5583 (11) Å and θ = 152°] may underl...