Crystal structure and Hirshfeld surface analysis of 2,2,2-trifluoro-1-(7-methylimidazo[1,2-a]pyridin-3-yl)ethan-1-one

The bicyclic imidazo[1,2-a]pyridine core in the molecule of the title compound, C10H7F3N2O, is planar within 0.004 (1) Å. In the crystal, the molecules are linked by pairs of C—H...N and C—H...O hydrogen bonds, forming strips. These strips are connected by the F...F contacts into layers, which are further joined by π–π stacking interactions. The Hirshfeld surface analysis and fingerprint plots reveal that molecular packing is governed by F...H/H...F (31.6%), H...H (16.8%), C...H/H...C (13.8%) and O...H/H...O (8.5%) contacts.

1,3-Thiazole-4-carbonitrile

The title compound, C4H2N2S, is a 1,3-thiazole substituted in the 4-position by a nitrile group. In the crystal, C—H...N hydrogen bonds and aromatic π–π stacking interactions are observed.

Synthesis, Crystal Structures, and Molecular Properties of Three Nitro-Substituted Chalcones

Three functionalized chalcones containing combinations of nitro functional groups have been synthesized via Claisen-Schmidt condensation between 2-nitroacetophenone and nitrobenzaldehyde, and the crystal structures obtained ((E)-1,3-bis(2-nitrophenyl)prop-2-en-1-one, 1a, (E)-1-(2-nitrophenyl)-3-(3-nitrophenyl)prop-2-en-1-one, 1b and (E)-1-(2-nitrophenyl)-3-(4-nitrophenyl)prop-2-en-1-one, 1c), C15H10N2O5, are reported. Compounds 1a and 1c crystallized in the triclinic centrosymmetric space group P1¯, whereas compound 1b crystallized in the orthorhombic space group Pbca. The X-ray analysis reveals that structures 1a and 1b exhibits s-trans conformation, whereas structure 1c exists in s-cis conformation, concerning the olefinic double bonds. In addition, the results show that the position of the nitro substituent attached to the aromatic B-ring has a direct effect on the molecular coplanarity of these compounds. The Hirshfeld surface analysis suggests that the non-covalent π-π stacking interactions are the most important contributors for the crystal packing of 1a and 1b. In 1c, the crystal packing is mainly stabilized by weak intermolecular C―H···O interactions due to the planar nature of the molecule.

Probing the adsorption behavior and free energy landscape of single–stranded DNA oligonucleotides on single–layer MoS2 with molecular dynamics

Interfacing single–stranded DNA (ssDNA) with 2D transition metal dichalcogenides are important for numerous technological advancements. However, the molecular mechanism of this process, including the nature of intermolecular association and conformational details of the self–assembled hybrids is still not well understood. Here, atomistic Molecular Dynamics (MD) simulation is employed to study the distinct adsorption behavior of ssDNA on a single–layer MoS2 in aqueous environment. The ssDNA sequences [T10, G10, A10, C10, U10, (GT)5, and (AC)5] are chosen on the basis that short ssDNA segments can undergo a spontaneous conformational change upon adsorption and allow efficient sampling of the conformational landscape. Differences in hybridization is attributed to the inherent molecular recognition ability of the bases. While the binding appears to be primarily driven by energetically favorable van der Waals π–stacking interactions, equilibrium structures are modulated by the ssDNA conformational changes. The poly–purines demonstrate two concurrently competing π–stacking interactions: nucleobase–nucleobase (intramolecular) and nucleobase–MoS2 (intermolecular). The poly–pyrimidines, on the other hand, reveal enhanced π–stacking interactions, thereby maximizing the number of contacts. The results provide new molecular–level understanding of ssDNA adsorption on the MoS2 surface and facilitate future studies in design of functional DNA/MoS2 structure–based platforms for DNA sequencing, biosensing (optical, electrochemical, and electronic), and drug delivery.

Synthesis and Characterization of New Guanine Complexes of Pt(IV) and Pd(II) by X-Ray Diffraction and Hirshfeld Surface Analysis

The aim of the work was to synthesize new perspective compounds of palladium and platinum with nitrogenous bases (guanine), promising for use in biomedicine and catalysis. The article describes the synthesis of new [PdCl2(HGua)2]Cl2·H2O and [PtCl5(HGua)]·2H2O compounds using wet chemistry methods. The structure of the obtained single crystals was established by the method of single crystal X-ray diffraction. The complexes have an M-N bond, and the organic ligand is included in the first coordination sphere. The analysis of Hirshfeld surfaces for the obtained complexes and their analogues for the analysis of intermolecular interactions was carried out. In the palladium complex we obtained, π-halogen and π-stacking interactions were found; in analogues, such interactions were not found. π-halogen and halogen interactions were found in structure of platinum complex and its analogues.

Co(NCS)2(abpt)2 and Ni(NCS)2(abpt)2 [abpt is 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole]: structural characterization of polymorphs A and B

The synthesis and structures of bis[4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole-κ2 N 2,N 3]bis(thiocyanato-κN)cobalt(II), [Co(NCS)2(C12H10N6)2] or Co(NCS)2(abpt)2, and bis[4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole-κ2 N 2,N 3]bis(thiocyanato-κN)nickel(II), [Ni(NCS)2(C12H10N6)2] or Ni(NCS)2(abpt)2, are reported. In both cases, two polymorphs, A and B, were identified and structurally characterized. For both polymorphs, the structures obtained with the different metals, i.e. CoII or NiII, were found to be isostructural. All of the structures contained an intramolecular N—H...N hydrogen bond, C—H...N interactions and π–π stacking interactions. No structural evidence was observed for a thermal spin crossover for either of the Co(NCS)2(abpt)2 polymorphs between 300 (2) and 120 (2) K.

Crystal structure and Hirshfeld surface analysis of 3-[2-(3,5-dimethylphenyl)hydrazinylidene]benzofuran-2(3H)-one

In the title compound, C16H14N2O2, the 2,3-dihydro-1-benzofuran ring system is essentially planar and makes a dihedral angle of 3.69 (7)° with the dimethylphenyl ring. The molecular conformation is stabilized by an intramolecular N—H...O hydrogen bond with an S(6) ring motif. In the crystal, molecules are connected by C—H...π and π–π stacking interactions, forming a layer lying parallel to the (11\overline{1}) plane. One methyl group is disordered over two orientations, with occupancies of 0.67 (4) and 0.33 (4). Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (51.2%), O...H/H...O (17.9%), C...H/H...C (15.2%) and C...C (8.1%) contacts.

New Copper (II) Isomer Based on 8-aminoquinoline Ligand: Synthesis, Molecular Structure, Hirshfeld Surface Analysis and Computational Study.

Toward the treating of a multifunctional material, new [Cu(H2O)2(C9H8N2)2]Cl2 isomer 1 has been synthesized by solvothermal method. The single-crystal X-ray study, Hirshfeld surface analysis and computational calculation were discussed. Hydrogen bonding network within the complex enable the formation of 3D network supported by aromatic stacking interactions of quinoline rings in face-to-face and edge-to face fashions. The analysis of Hirshfeld surfaces, facilitate a comprehension of intermolecular interactions in the structure. The enrichment ratio (E) was calculated to examine the propensity of intermolecular interactions to form contacts in crystals. It shows that the favorable contacts responsible for the crystal packing are strong hydrogen bonds and stacking interactions. The reactivity descriptors for 1 such as EHOMO and ELUMO energies, ionization potential (IP), Electron affinity (EA), Mulliken electronegativity (χ) and the Absolute hardness (η) was calculated by PBE functional method with DNP basis set. The possible sites for nucleophilic and electrophilic attacks on 1 were analyzed through Fukui functions.