Types Of Intermolecular Interactions Research Articles

Building-up novel coordination polymer with magnesium porphyrin: Synthesis, molecular structure, photophysical properties and spectroscopic characterization. Potential application as antibacterial agent

The new meso-tetraphenylporphyrin magnesium(II) polymer compound with the formula {[MgII(TPP)(4,4′-bpy)]}n.n[MgII(TPP)(4,4′-bpy)2] (I), (TPP) = meso-tetraphenylporphyrinato and 4,4′-bipy = 4,4′-bipyridine) was synthetized and characterized by IR, UV–visible, photoluminescence and 1H NMR spectroscopy studies, single-crystal XRD analyses and cyclic voltammetry. From the X-ray data, it was established that the central metal Mg2+ is located on an inversion center, being octahedrally coordinated to four pyrrole nitrogen atoms of the porphyrin ring and the nitrogen atoms of the two 4,4′-bipyridine axial ligand situated in trans positions with respect to the metal center. The crystal of (I) is made by [MgII(TPP)(4,4′-bipy)2] monomer complexes and {[MgII(TPP)(4,4′-bpy)]}n polymers linked together via CH…π type intermolecular interactions leading to a three-dimensional network. The UV–visible spectrum of (I) shows that the Soret band value (432 nm) is redshifted compared to the free base H2TPP while the λmax values of the Q bands are in the range 570–610 nm. The optical gap of (I) was estimated at 2.00 eV and the cyclic voltammogram of the title compound presents two reversible oxidation waves and one reversible reduction wave. The HOMO and LUMO energy values were deduced from the voltammogram which are −4.94 and −3.06 eV respectively. The use of [MgII(TPP)(DMF)] starting material compound, {[MgII(TPP)(4,4′-bpy)]}n.n[MgII(TPP)(4,4′-bpy)2] (I) and the [MgII(TPP)(HTMA)2] (HTMA = hexamethylenetetramine) (II) as novel significant antibacterial agents was also tested.

Bimetallic and trimetallic Cd(II) and Hg(II) mixed-ligand complexes with 1,1-dicyanoethylene-2,2-dithiolate and polyamines: Synthesis, crystal structure, Hirshfeld surface analysis, and antimicrobial study

Two new neutral bimetallic and trimetallic mixed-ligand complexes of Cd(II) and Hg(II) were obtained by using potential flexible molecular building blocks, 1,1-dicyanoethylene-2,2-dithiolate dipotassium salt (K2i-mnt) and polyamines. X-ray diffraction analysis revealed that dithiolate (i-mnt−2) acts as a bridging unit in the slightly distorted square pyramidal non-polymeric bimetallic cadmium derivative [Cd2(tn)2(i-mnt)2] (1). The tri-metallic Hg(II) based cocrystallized aggregates of [Hg2(tren)(i-mnt)2] and [Hg(tren)(i-mnt)](2), has three different coordination environments around Hg(II) metal centers and one thiolate end of i-mnt−2 links two Hg atoms in bridging mode. The N–H⋯S, N–H⋯N, C–H⋯S and C–H⋯N type hydrogen bonds contribute in crystal packing architecture, revealing interesting geometrical patterns and graph-set-motifs. The Hirshfeld surface mapped over dnorm exhibited N⋯H/H⋯N type intermolecular interactions as the principal contributors in crystal packing. The in-vitro antimicrobial study evaluated by disk diffusion and broth dilution method with the compounds 1,2 and ligand K2i-mnt against Gram-positive (Staphylococcus aureus 9542 and Streptococcus pneumonia 2672) and Gram-negative (Klebsiella pneumonia 7407 and Shigella flexneri 1457) human pathogenic bacterial strains show their promising antimicrobial activities.

Synthesis, Characterization and Hirshfeld Surface Analysis of a 2-thiophene Acetic Acid Derivative

N,N′-dicyclohexylcarbamoyl-2-(thiophen-2-yl)acetamide (C19H28N2 O2S), was prepared using 1,3-dicyclohexylurea. The compound has been characterized by IR, and single-crystal X-ray diffraction followed by a detailed Hirshfeld surface analysis. The compound crystallizes in the monoclinic space group P21/c, with cell parameters a = 9.0969(3) Å, b = 18.3067(5) Å, c = 11.6499(3) Å, β = 103.876(2)°, V = 1883.49(10) Å3, Z = 4. The crystal structure of the compound is stabilized by the intermolecular interactions of types N–H…O, C–H…O and intramolecular interactions of the type C–H…O.

Synthesis, Crystal Structure, and Characterization of (Z)-2-(3-chlorophenyl)-N’-hydroxyacetamidine

The compound (Z)-2-(3-chlorophenyl)-N’-hydroxyacetamidine, (2) was synthesized and characterized by 1H NMR, FT-IR, TGA, UV-Visible Spectra, and elemental analysis. Its molecular structure was solved by single-crystal X-ray diffraction method. The title molecule, C8H9ClN2O is crystallized in the monoclinic crystal system with the space group P21/c and with unit cell parameters a = 8.7092(4) Å, b = 8.2370(4) Å, c = 12.5256(6) Å, β = 102.252(3)°, and Z = 4. The molecular and crystal structure of the title molecule is stabilized by an intramolecular interaction of the type N—HċċċO, and the intermolecular interactions of types N—HċċċN and O—HċċċN.

Synthesis, Crystal Structure and Characterization of (Z)-2-N′-hydroxyisonicotinamidine

The compound (Z)-2-N′-hydroxyisonicotinamidine, (2) was synthesized and characterized by 1H NMR, FT-IR, FAB-Mass, UV-Visible Spectra, and elemental Analysis. Its molecular structure was solved by single crystal X-ray diffraction method. The title molecule, C6H7N3O is crystallized in the orthorhombic crystal system with the space group Pna21 and with unit cell parameters a = 12.5664(8) Å, b = 8.8622(6) Å, c = 5.7953(4) Å, α = 90°, β = 90°, γ = 90°, and Z = 4. The molecular and crystal structure of the title molecule is stabilized by an intramolecular interaction of the type N—H···O, and the intermolecular interactions of types N—H···N and O—H···N.

Synthesis, Crystal Structure, and Characterization of New 2,4,5-Triphenyl Imidazole: 4,5-Diphenyl-2-(3,4,5-trimethoxyphenyl)-1H-imidazole

The substituted triarylimidazole, C24H22N2O3, was prepared from the three-component one-pot condensation reaction and the product was crystallized by using dimethylformamide. The structure of the compound was confirmed by elemental analysis, FT-IR, thermogravimetric analysis (TGA), UV-Visible and single-crystal X-ray diffraction. The compound crystallizes in the monoclinic crystal system in the space group P21/c with unit cell parameters a = 10.509(3) Å, b = 18.748(5) Å, c = 22.016(6) Å, β = 90.844(5)°, and Z = 8. The crystal structure of the compound was stabilized by the inter-molecular interactions of types N–H⋅⋅⋅N, C–H⋅⋅⋅O, and C–H⋅⋅⋅N, and intra-molecular interactions of the type C–H⋅⋅⋅O. The structure also involves C–H⋅⋅⋅π interactions.

Molecular Interactions by Ultrasonic Velocity, Density and Viscosity Measurements in Binary Mixtures at 303 K and 4 MHz Frequency

The density, ultrasonic velocity and viscosity at temperature 303K and 4MHz frequency have been measured in the binary systems of Cinnamaldehyde with non-polar liquid 1, 4- dioxane. From the experimental a f data, various acoustical parameters such as adiabatic compressibility (â ), intermolecular free length (L ) and free f volume (V ) were calculated. It has been observed that, weak dispersive type intermolecular interactions are confirmed in the system investigated. The results are interpreted in terms of molecular interaction between the components of the mixtures.

Physico-chemical and excess thermodynamic properties of methanol & ethanol with 1, 4-dioxane at 308 K

The molecular interaction studies in the binary liquid mixtures of two aliphatic alcohols with 1, 4-dioxane has been carried out at 308 K using ultrasonic technique. Using measured values of ultrasonic velocity, density and viscosity, acoustical parameters such as adiabatic compressibility, free volume, free length and their excess values like VfE, ßaE, LfE are evaluated. From the properties of these excess parameters, the nature and the strength of interactions in these binary systems are discussed. It has been observed that, weak dispersive type intermolecular interactions are confirmed in the systems investigated. Dipole inducement is found to be more predominant in methanol system.

Pillaring Role of 4,4′-Azobis(pyridine) in Substituted Malonate-Containing Manganese(II) Complexes: Syntheses, Crystal Structures, and Magnetic Properties

Six new manganese(II) complexes of formulas [Mn2(Rmal)2(H2O)2(azpy)]n (1–3), [Mn(Phmal)(H2O)(azpy)]n (4), [Mn2(Et2mal)2(H2O)4(azpy)2]n (5), and [Mn(Bzmal)(H2O)3(azpy)] (6) [azpy = 4,4′-azobispyridine (1–6), Rmal = methylmalonate (Memal) (1), dimethylmalonate (Me2mal) (2), and butylmalonate (Butmal) (3), Phmal = phenylmalonate (4), Et2mal = diethylmalonate (5), and Bzmal = benzylmalonate (6)] were synthesized and structurally characterized by single-crystal X-ray diffraction. Complexes 1–3 are three-dimensional compounds whose structure consists of corrugated layers of manganese(II) linked through syn–anti carboxylate (Rmal) bridges, which are pillared through the bis-monodentate azpy molecule. Complex 4 has a layered structure of manganese(II) ions connected by carboxylate (Phmal) bridges in the syn–anti coordination mode as in 1–3, the azpy group acting here as a terminally bound monodentate ligand. The structure of 5 consists of Et2mal–Mn(II) neutral chains linked through the azpy ligand, giving rise to a complex three-dimensional network. Complex 6 is constituted by neutral [Mn(Bzmal)(H2O)3(azpy)] mononuclear units, which are interlinked through O–H···O, O–H···N, and π–π type intermolecular interactions to afford a three-dimensional supramolecular structure. The topological analysis of these crystallographic structures shows the occurrence of four different nets: a (3,4)-connected InS-type (1–3), a binodal layered hcb (4), a uninodal CdS-type (5), and a (4,5)-connected tcs topology (6). The magnetic properties of 1–5 were investigated in the 2.0–300 K temperature range. Overall antiferromagnetic behavior occurs in 1–4 with susceptibility maxima in the range 2.8–5.5 K, the exchange pathway being provided by the syn–anti carboxylate (substituted malonate) bridge [manganese–manganese separation in the range 5.4365(3)–5.5274(1) Å]. Very weak antiferromagnetic interactions are observed in 5 through the trans-bis-monodentate Et2mal ligand, the intrachain manganese–manganese separation being 7.328(3) Å. The much larger manganese–manganese separation through the bis-monodentate azpy ligand in 1–5 (values greater than 13.5 Å) accounts for the lack of any significant magnetic interaction though this extended bridge.

Crystal Structure and Conformational Analysis of 4-[(p-N,N-Dimethylamino)Benzylidene]-2-Phenyloxazole-5-One

Molecular and crystal structure of 4-[(p-N,N-dimethylamino)benzylidene]-2-phenyloxazol-5-one, C18H16N2O2, have been determined by single crystal X-ray diffraction study. The title compound is monoclinic, with a = 12.1704(23) A, b = 3.9810(5) A, c = 30.9603(56) A, β = 101.176(15)°, Z = 4, D x = 1.32 g/cm3, μ(Mo Kα) = 0.087 mm−1, and space group is P121/c1. The structure was solved by direct methods and refined to a final R = 0.047 for 3166 reflections with I > 2σ(I). The crystal structure is stabilized by C–H⋯O and C–H⋯N type intra-molecular, C–H⋯O type inter-molecular interactions. To enlighten the flexibility and the geometric isomerism (E or Z) of the title compound, the selected torsion angle is varied from −180 to 180° in every 10° separately and molecular energy profile is calculated and analyzed. Molecular and crystal structure of 4-[(p-N,N-dimethylamino)benzylidene]-2-phenyloxazole-5-one, C18H16N2O2, have been determined by single crystal X-ray diffraction study, and then conformational analysis of the title molecule with respect to the selected torsion angle has been achieved by DFT using B3LYP hybrid functional.

Crystal Structure and Conformational Analysis of 4-[(p-N,N-Dimethylamino) benzylidene]-2-(3,5-dinitrophenyl)oxazole-5-one

ABSTRACT An azlactone derivative, 4-[(p-N,N-dimethylamino)benzylidene]-2-(3,5-dinitrophenyl)oxazol-5-one (DNPO), C18H14N4O6, has been synthesized, and its crystal structure has been investigated by single crystal X-ray analysis and ab initio method. DNPO is monoclinic, with a = 9.3628(4) Å, b = 13.5148(9) Å, c = 13.7701(6) Å, β = 92.921(4)°, Z = 4, Dx = 1.46 g/cm3, μ(MoKα) = 0.112 mm−1, and space group P 121/c1. The whole molecule is almost planar. The crystal structure is stabilized by C–H · · · N type intramolecular, C–H · · · O type intermolecular interactions. To determine the flexibility of DNPO, the selected torsion angle is varied from − 180° to 180° in steps of 10°, and the molecular energy profile is calculated and analyzed.

Synthesis, characterization and thermal decomposition of dioxouranium(VI) complexes with N1, N4-diarylidene- S-propyl-thiosemicarbazone: Crystal structure of [UO 2(L I)(C 4H 9OH)

Reactions of salicyl- and 3,5-dichlorosalicylaldehyde- S-propyl-thiosemicarbazones with salicyl- and 3,5-dichlorosalicylaldehyde in the presence of UO 2(CH 3COO) 2 in different alcohols yielded stable solid complexes corresponding to the general formula [UO 2(L)ROH] (R: propyl-, butyl-, pentyl-, and octyl-). The complexes were characterized by means of elemental analysis, IR and 1H NMR spectroscopies. The thermal stabilities of the alcohol solvated complexes were investigated in air and nitrogen atm., and determined their decomposition phases. In the crystal structure of the [UO 2(L)(C 4H 9OH)], the U( VI) centre is seven-coordinated in a distorted pentagonal bipyramidal geometry involving O,O,N,N atoms of two phenolic and two imine groups and one oxygen atom of alcohol molecule in basal plane and two O atoms of dioxo group in apical positions. The title structure is stabilized by one intramolecular interaction of types C–H⋯Cl and by two intermolecular interactions of types O–H⋯O and C–H⋯π (benzene) leading to the molecular chain along the [0 1 0] direction.

Desynchronization of Pedal Motion: Crystallographic and Theoretical Study of (E)-4-[(4-ethylphenyl)diazenyl]-2-methylphenol

The single crystal X-ray diffraction analysis of the title compound, C15H16N2O, reveals that its molecules exhibit whole-molecule disorder at both crystal lattice sites due to pedal motion in solid state. The compound crystallizes in the monoclinic space group P 21/c with a = 20.5504(14) A, b = 10.8887(5) A, c = 12.0191(8) A and β = 96.927(5)°. While major pedal conformers of the compound in solid state are stabilized by intermolecular O–H···N type hydrogen bonds leading to the formation of C(7) chains at Site 1 and C(8) chains at Site 2 along [0 1 0] axis, C–H···π type intermolecular interactions between major and minor conformers also serve to stabilize minor pedal conformers. An interesting feature about the crystal structure is that pedal conformers at Site 1 have two different occupancy factors arising from desynchronization of pedal motion along [2 1 0] direction in crystal phase. Quantum chemical calculations at the B3LYP/6-31++G** level suggest that the desynchronization of pedal motions make more unstable pedal conformers at Site 1 than those at Site 2. Molecular and crystal structure of (E)-4-[(4-ethylphenyl)diazenyl]-2-methylphenol, C16H18N2O, indicate desynchronization of pedal motion and the quantum chemical calculations at level of B3LYP/6-31++G** suggest that desynchronization of pedal motions make more unstable pedal conformers.

2-[(4-Phenylthiazol-2-yl)hydrazonomethyl]phenol

In the title compound, C16H13N3OS, the plane of the —C—CH=N—NH—C— bridge makes dihedral angles of 7.9 (2) and 11.9 (4)° with the planes of the phenol and thia­zole rings, respectively. In the mol­ecule, there are two intramolecular interactions of type O—H⋯N and C—H⋯N. In the crystal structure, there are two intermolecular interactions of type C—H⋯N and N—H⋯O, leading to the formation of dimers.

Benzoin thiosemicarbazone

In the title compound, C15H15N3OS, the thio­semicarbazone moiety is planar, with a maximum deviation of 0.0369 (11) A, and has an E configuration. The planar phenyl rings make dihedral angles of 26.56 (9) and 81.20 (5)° with the plane of the thio­semicarbazone moiety. In the mol­ecule, there are two intramolecular interactions of types N—H⋯O and N—H⋯N. In the crystal structure, there are two intermolecular interactions of types O—H⋯S and N—H⋯S, leading to the formation of dimers.

Fluorescence Spectra for the Microcrystals and Thin Films of trans,trans,trans-1,6-Diphenyl-1,3,5-hexatrienes

The absorption and fluorescence spectra, fluorescence quantum yields (φflu), and lifetimes (τs) for the microcrystals and vacuum deposited thin films of the p,p‘-disubstituted trans,trans,trans-1,6-diphenyl-1,3,5-hexatrienes (DPHs) 1−10 have been measured and compared with those in dilute solutions at room temperature and in organic glasses at 77 K. The positions of the peaks at the shortest wavelengths in the fluorescence main bands, which are mainly determined by effective π-conjugation lengths (ECLs) in the excited state, are tuned in the visible spectral range 463−587 nm by introduction of various substituents. The fluorescence main bands shift to longer wavelengths as the strength of electron-donating/withdrawing substituents on the aromatic ring increases. The fluorescence spectra of the microcrystalline samples are more strongly dependent on substituents than those of samples in solution, because of strong charge transfer (CT) type intermolecular interactions induced by substituents in the solid state. The solid-state fluorescence spectra of the derivatives with electron-donating N,N-dimethylamino and methoxy groups (1 and 2, respectively) are red-shifted and structured, probably due to the formation of ground-state aggregates. The spectrum for the thin film of 2 shows a close resemblance to that for the thin film of high molecular weight poly(1,4-phenylenevinylene) (PPV), suggesting similar ECLs for 2 and PPV in the excited states. The spectra of the derivatives with electron-withdrawing substituents, on the other hand, are red-shifted and structureless. The broad fluorescence observed for the diformyl derivative (6) is assigned to excimer emission.

Crystal Structure Analysis of 3'5' (dichloro phenyl)-3-ethyl-5-phenyl thio indalo [1,2-e] imidazolidine

The title compound crystallizes in monoclinic system with space group P2 1 /n. The cell parameters are a = 12.3824(3) A, b = 8.9255(1) A, c = 19.9188(4) A, V = 2181.75(7) A 3 , α = γ = 90.0° and β = 97.663(1)°. The structure has an indole moiety and an imidazolidine ring connected together. The phenyl sulfonyl group is attached to the indole moiety and the dichlorophenyl ring to the imidazolidine ring. The structure has a C-H…Cl intra molecular hydrogen bond and C-H…π type intermolecular interactions.

2-Phenyl-4-(p-toluidinomethylene)-5-oxazolone

The two crystallographically independent mol­ecules in the asymmetric unit of the title compound, C17H14N2O2, have nearly the same molecular geometry. The planarity of the oxazoline ring is not affected by substitutions at the 2 and 4 positions. The structure is stabilized by N—H⋯O type intermolecular interactions.

Crystal and molecular structure of Dicyanotetrasulfane S4(CN)2

AbstractS4(CN)2 crystallizes in the monoclinic space group P21/c with a = 885.7 pm, b = 794.2 pm, c = 1032.6 pm, β = 109.0° (at 173 K). The molecules occupy general sites but are of approximate C2 symmetry. The conformation of the molecules is all‐trans with torsional angles CSSS = 74.6° and 81.7° and SSSS = 84.8°. The central SS bond (201.7 pm) is much shorter than the terminal SS bonds (av. 206.8 pm). There are no stronger than van‐der‐Waals type intermolecular interactions.

Molecular dynamics simulation study of solid polyphenyls: Structures determined by the interplay between intra- and intermolecular forces

As a continuation of our previous work we have performed constrained molecular dynamics simulations on models of solid biphenyl and para-terphenyl in order to study their conformation instability. We determined a ‘critical’ torsion potential range with respect to widely used Williams type intermolecular interactions and the experimentally determined densities. Torsion potentials weaker than this critical one will not produce phase transitions. The critical torsion potential was found to be similar for both molecules in the solid state. The fine details of the structures for both compounds vary with simulation parameters but the major characteristics of the arrangements are rather insensitive in this respect. We compared our findings with experimental results. For biphenyl—as we reported in our previous paper—our results are qualitatively different from the structure assumed from X-ray diffraction measurements. Rather than all the molecules having the same torsion angle on average, alternate molecules in the b direction have a very small (0–2°) or a much larger (∼22°) torsion angle. For p-terphenyl our results are qualitatively in agreement with what was found in X-ray measurements, with each of four molecules in the low temperature unit cell having different torsion angles. However, the same trends as for biphenyl were observed with at least one of the sites containing molecules with a very small torsion angle.