Synthesis, crystal structure and Hirshfeld surface analysis of copper(I) nitrate -complex based on 1-(2,6-dimethylphenyl)-5-allylsulfanyl-1H-tetrazole

By means of the alternating current electrochemical technique and starting from copper wire electrodes in propanol solution of corresponding ligand and copper(II) nitrate, novel copper(I) -complex [Cu2(C12H14SN4)2(NO3)2] (1) has been obtained and X-ray structurally investigated: sp. gr. , a=7.352(3) Å, b=8.269(3) Å, c=12.723(4) Å, =82.08(3)0, =82.74(3)0, =88.37(3)0, V=759.9(5) Å3, Z=2, dcalc=1.625 g cm–3, (CuK)=3.502 mm–1, max=67.960, 4119 measured reflections, 1248 used reflections, 201 refined parameters, R(F2)=0.0915, S=0.95. The trigonal-pyramidal copper(I) coordination environment consists of nitrogen atom and allylic group of ligand, and of two oxygen atoms from crystallographically distinct nitrate anions. Due to a bridging function of oxygen atoms of nitrate anions, two metal-containing polyhedra are connected into {Cu2L2(NO3)2} topological units which are additionally stabilized by noncovalent interaction CuO(2). Comparatively weak hydrogen bonds C–HO exist in the crystal structure of [Cu2(C12H14SN4)2(NO3)2] (1).

A hybrid molecular peapod of sp2- and sp3-nanocarbons enabling ultrafast terahertz rotations

The internal hollow space of carbon nanotubes provides a unique nanometre-sized space to capture various molecular entities. The inner space circumfused by sp2-carbon networks can also encapsulate diamondoid molecules to afford sp2/sp3-hybrid nanocarbon peapods that have recently emerged as unique nanostructures. In this study, the sp2/sp3-hybrid peapods have been mimicked by adopting a cylindrical molecule and the smallest diamondoid, i.e., adamantane, to demonstrate the existence of ultrafast rotational motion. The solid-state rotational frequency is measured by NMR spectroscopy to record 1.06 THz that is, to the best of our knowledge, the largest value recorded for solid-state rotations of molecules. Theoretical calculations reveal that multivalent CH-π hydrogen bonds anchored the diamondoid guest on the π-wall of the cylindrical host. The weak hydrogen bonds are prone not only to cleave but also to regenerate at the interfaces, which give freedom to the guest for ultrafast isotropic rotations in the inertial regime.

Raman spectroscopy shows difference in drugs at ultra high dilution prepared with stepwise mechanical agitation

Objective The present study aims at deciphering the nature of the water structure in two drugs at ultra high dilution (HD) by Laser Raman Spectroscopy. Method Two drugs like Sulphur and Natrum mur and their three high dilutions 30cH, 200cH and 1000cH were selected for the study. The 30cH means dilution 1060 with mechanical agitation in 30 steps.Raman spectra of the drugs and their medium (90%ethanol)were obtained in the wave number region of 2600-3800 cm-1. The intensity ratio at vibration frequencies between 3220 and 3420 (R1) and that between 3620 and 3420 (R2) were calculated for each HD as well as the control. Results Raman spectra show differences in intensities in different HD’s and their control in the stretching vibrations of CH and OH groups. The three HD’s of each drug show inverse relationship with respect to the R1 values. However, for R2 the relationship of HD’s for each drug is positive. Conclusion R1 provides information about the relative number of OH groups with strong and weak hydrogen bonds. R2 suggests the relative number of OH groups with broken and weak hydrogen bonds. Judged from R1 values the lower is the rank of HD, the stronger is the H-bond of the OH groups. In the light of R2 values the higher is the HD rank the more abundant is the free OH groups. So, hydrogen bond strength and free OH groups together make an effective HD rank relating to Sulphur and Natrum mur.

Crystal structure and Hirshfeld surface analysis of ethyl 2-[9-(2-hydroxyphenyl)-3,3,6,6-tetramethyl-1,8-dioxo-2,3,4,4a,5,6,7,8a,9,9a,10,10a-dodecahydroacridin-10-yl]acetate

In the title compound, C27H33NO5, a 3,3,6,6-tetramethyltetrahydroacridine-1,8-dione ring system carries an ethyl acetate substituent on the acridine N atom and an o-hydroxyphenyl ring on the central methine C atom of the dihydropyridine ring. The benzene ring is inclined to the acridine ring system at an angle of 80.45 (7)° and this conformation is stabilized by an intramolecular O—H...O hydrogen bond between the hydroxy substituent on the benzene ring and one of the carbonyl groups of the acridinedione unit. The ester C=O oxygen atom is disordered over major and minor orientations in a 0.777 (9):0.223 (9) ratio and the terminal –CH3 unit of the ethyl side chain is disordered over two sets of sites in a 0.725 (5): 0.275 (5) ratio. In the crystal, C—H...O hydrogen bonds combine to link the molecules into a three-dimensional network. van der Waals H...H contacts contribute the most to the Hirshfeld surface (66.9%) followed by O...H/H...O (22.1%) contacts associated with weak hydrogen bonds.

Weak Interactions in the Structures of Newly Synthesized (–)-Cytisine Amino Acid Derivatives

Eight new (–)-(N-[(AA)-(N-phtaloyl)]cytisines (where AA is amino acid: glycine, β-alanine, D,L-valine, L-valine, L-isoleucine, L-leucine, D-leucine and D,L-phenyloalanine), were synthesized and fully spectroscopically characterized (NMR, FTIR and MS). For two of these compounds, N-[glycine-(N-phtaloyl)]cytisine and N-[L-isoleucine-(N-phtaloyl)]cytisine, X-ray crystal structures were obtained and used as the basis for an in-depth analysis of intermolecular interactions and packing energies. The structural geometrical data (weak hydrogen bonds, π···π interactions, etc.) were compared with the energies of interactions and the topological characteristics (electron density, Laplacian at the appropriate critical point) based on the atoms-in-molecules theory. The results suggest that there is no straightforward connection between the geometry of point-to-point interactions and the molecule-to-molecule energies. Additionally, the usefulness of the transfer of multipolar parameters in estimating of critical points’ characteristics have been confirmed.

Aggregation of coronene: the effect of carboxyl and amine functional groups

Global optimization reveals that aggregation is enhanced for coronene substituted with carboxylic and amine groups, which is due to the influence of weak hydrogen bonds and stronger electrostatic contributions.

Isostructurality of Quinoxaline Crystal Phases: The Interplay of Weak Hydrogen Bonds and Halogen Bonding

Tailoring the physical properties of molecular crystals though the construction of solid solutions requires the existence of isostructural crystals. Simple substitutions of a given molecular framework can give a range...

Coordination-Bond-Directed Synthesis of Hydrogen-bonded Organic Frameworks from Metal–Organic Frameworks as Templates

Controlled synthesis of hydrogen-bonded organic frameworks (HOFs) remains challenging, because the self-assembly of ligands is not only directed by weak hydrogen bonds, but also affected by other competing van der...