The conformation of dimethyl (R,R)-tartrate has been analyzed on the basis of the single crystal X-ray diffraction method as well as by ab-initio quantum chemical studies. The results showed that the extended T conformation containing two planar hydroxyester moieties predominates in both ab-initio and X-ray studies. The lowest energy conformer in ab-initio calculations has C2 symmetry and hydro...

The title compound, C(5)H(10)NO(+)·HSO(4) (-), has been synthesized by reaction of 1-methyl-pyrrolidin-2-one with H(2)SO(4) in a 1:1 molar ratio. The substituted pyrrolium ring adopts an envelope conformation. The hydrogensulfate anions form infinite helical chains parallel to the a axis via strong O-H⋯O hydrogen bonds. The pyrrolium cations are pendant from the chains. These cations are the hy...

In the title compound, C(26)H(20)N(6)O(4), the two aroylhydrazone side groups exist as diastereomeres, both in the keto form in the crystal structure. The aroylhydrazone units support the mol-ecular conformation through an intra-molecular N-H⋯O hydrogen bond. Two mol-ecules are connected into a centrosymmetric dimer by inter-molecular N-H⋯N hydrogen bonds. These dimers are connected into chains...

In the title salt, C(6)H(10)N(3)O(2) (+)·C(7)H(7)O(3)S(-), the 2-amino-4,6-dimeth-oxy-pyrimidinium cation inter-acts with the sulfonate group of the p-toluene-sulfonate anion via a pair of N-H⋯O hydrogen bonds, forming a cyclic hydrogen-bonded R(2) (2)(8) motif, which in the crystal is linked by further intemolecular N-H⋯O hydrogen bonds, forming supra-molecular chains along the c axis. Further...

Charge densities have been determined by the Maximum Entropy Method (MEM) from the high-resolution, low-temperature (T approximately 20 K) X-ray diffraction data of six different crystals of amino acids and peptides. A comparison of dynamic deformation densities of the MEM with static and dynamic deformation densities of multipole models shows that the MEM may lead to a better description of th...

The title compound, C15H13ClN2O2S, exists in the solid state in its thione form with typical thio-urea C-S and C-O bonds lengths as well as shortened C-N bonds. An intra-molecular N-H⋯O hydrogen bond stabilizes the mol-ecular conformation. In the crystal, N-H⋯S hydrogen bonds link the mol-ecules into centrosymmetric dimers.

a theoretical density functional theory (dft) study was performed on a series of the neutral n-phenylthiourea substituents (p-oc2h5, p-ch3, m-ch3, h, p-cl, p-br, m-cl, and p-no2) as the sensor of acetate and fluoride anions. the hydrogen bond character was analyzed as a scale of the sensing activity. it was confirmed that hydrogen bond between the p-no2 derivatives of n-phenylthiourea and fluor...

a new proton transfer compound, formulated as (hamp-6-pic)(hpyzd) ∙h2o (1), has been synthesized from the reaction of pyrazine-2,3-dicarboxylic acid (h2pyzd)  and 2-amino-6-methyl pyridine (amp-6-pic), in 1:1 molar ratio. extensive o−h×××o, n−h×××n and o−h×××o hydrogen bonds involving (hamp-6-pic)+ cation, (hpyzd)- anion and co-crystal water molecule٫ static electronic٫ and π…π stacking interac...