A Hirshfeld surface analysis,crystal structure,and physicochemical studies of a new Cu(II) complex with the 1,10-phenanthroline ligand

Abstract

The new coordination compound, [Cu(H₂PO₄)₂(C₁₂N₂H₈)H₂O]·2H₂O, was prepared and characterized by physico-chemical studies. In this monomeric complex, the central Cu(II) atom is in a square pyramidal environment and chelated by two nitrogen atoms of 1,10-phenanthroline, two dihydrogeno-monophosphate oxygen atoms and one water oxygen atom. Intermolecular interactions were investigated by Hirshfeld surfaces. The ³¹P NMR spectrum of this paramagnetic complex displays a relatively sharp peak at 2,070?ppm. The vibrational absorption bands were identified by infrared spectroscopy. Electronic properties such as HOMO and LUMO energies were derived.     

Synthesis,spectroscopic studies,and single-crystal structures of two 3-D supramolecular zinc(II) and nickel(II) complexes containing thiazole ring: Antimicrobial assays,time-dependent density functional theory calculations,and Hirshfeld surface analysis

Two novel complexes [Zn( L )₂·(NO₃)₂] ( 1 ) and [Ni( L )₂·2H₂O]·2CH₃OH·(NO₃)₂ ( 2 ) ( L = 2-(2-thiazolyl)-4-methyl-1,2-dihydroquinazoline-N³-oxide) were synthesized successfully and characterized by elemental analysis, as well as various spectroscopic techniques. Specifically, the photoluminescence behavior of complex 1 was explored in different solvents. The structural characterization of both complexes has been determined single-crystal X-ray diffraction. It revealed that the metals in 1 and 2 are chelated by two L ligands in centro-symmetrically fashion and the complexes are counterbalanced by nitrate ions which act as coordinating species in 1 , while two water molecules complete the Ni coordination sphere in 2 . In the crystal structures, the adjacent molecules of complex 1 disclosed a ladder-like 2-D network and 3-D supramolecular self-assembly. Simultaneously, an infinite 1-D chain, 2-D layered skeleton, and even meter-shaped 3-D network of 2 was governed by molecular interactions (H–bonds, C–H⋯π). Most strikingly, the research of antibacterial activity proved that two complexes had good activity against two standard bacteria strains. To ascertain deeply the optimum geometric configurations and detect the frontier molecular orbital energy gaps, density functional theory (DFT) calculations were also investigated. Additionally, analyses of Hirshfeld surfaces (HS) and electrostatic potential (ESP) were also performed to quantify the presence of diverse noncovalent interactions.     

Two dinuclear copper (II) and nickel (II) complexes based on 4‐(diethylamino)salicylaldehyde: X‐ray structures,spectroscopic, electrochemical,antibacterial, Hirshfeld surfaces analyses,and time‐dependent density functional theory calculations

The quinazoline‐type ligand 2‐(4‐diethylamino‐2‐hydroxyphenyl)‐4‐methyl‐1,2‐dihydroquinazoline 3‐oxide ( HL ¹ ; H is the deprotonatable hydrogen) was prepared. Two 2‐D supramolecular complexes [Cu₂( L ² )₂(NO₃)₂] ( 1 ) and [Ni₂( L ² )₂(CH₃COO)₂] ( 2 ) ( L ² = 1‐(2‐{[(E)‐(4‐diethylamino‐2‐hydroxybenzylidene]amino} phenyl)ethanone oxime) were synthesized using HL ¹ and characterized by elemental analysis, spectroscopic methods, and single‐crystal X‐ray diffraction studies. It revealed that 1 had coordinated two nitrate ions whereas 2 had acetate ions. In the crystal structures, six‐coordinated Cu (II) complex 1 formed an infinite 2‐D and X‐shaped 3‐D supramolecular frameworks. Simultaneously, Ni (II) complex 2 assembled into wavy 2‐D networks. Furthermore, electrochemical properties and antimicrobial activities of all compounds were as well investigated. Afterwards, the electrophilic and nucleophilic attack sites identified by electrostatic potential (ESP) calculations confirmed that hydrogen bonds were observed in the optimized structure of the crystal, and the closest contact between the active atoms of both complexes was confirmed through Hirshfeld surface analysis and time‐dependent density functional theory (TD‐DFT) calculations.     

Synthesis,structures and Hirshfeld surface analysis of Ni(II) and Co(III) complexes with N2O donor Schiff base ligand

Two octahedral complexes [NiL(HL)]ClO₄.0.5CH₃OH and [CoL₂]ClO₄ have been synthesized with N₂O donor Schiff base ligand {((2-(phenylamino)ethyl)imino)methyl}phenol (HL) and characterized by spectroscopic techniques and single crystal X-ray diffraction studies. The molar conductivities data of the two complexes show that the complexes are 1:1 electrolyte. Single crystal X-ray diffraction data shows both Ni(II) and Co(III) complexes have distorted octahedral geometry and two ligands are coordinated to the metal centers and one ClO₄⁻ ion outside the coordination sphere. The intermolecular interactions in the complexes are evaluated by Hirshfeld surface analysis and revealed a significant contribution of non- or weakly polar interactions to the packing forces for both molecules, with crystal structure of Co(III) complex featuring short H/H contacts.     

Synthesis,crystal structure and Hirshfeld surface analysis of a new 0D nanostructured [{Ar-Cl)tetra-azo-S}2Hg] coordination supramolecular compound derived from phenyl isothiocyanate ligand

Abstract

Nanoparticles of a new mercury(II) coordination supramolecular compound (CSC), [{(Ar-Cl)tetra-azo-S}₂Hg] (1), were synthesized using a sonochemical process and characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and elemental analyses (EA). The single crystal X-ray data of 1 revealed that the Hg ion was two-coordinate. Also, Hirshfeld surface analysis of 1 showed the effective role of interactions related to nitrogen atoms in stabilization of the supramolecular structure. The role of ultrasonic power, sonicating time and temperature on the size and morphology of the nano-structured compound obtained from 1 were investigated. The results indicated that increasing temperature and sonication power and decreasing sonication time led to reducing the particle size.     

Syntheses,supramolecular networks and Hirshfeld surface and thermal analyses of two new cadmium chloride coordination polymers with an N,O‐chelating ligand

Two new coordination polymers, namely poly[[(3‐aminopyrazin‐4‐ium‐2‐carboxylate‐κ²N¹,O)di‐μ‐chlorido‐cadmium(II)] monohydrate], {[CdCl₂(C₅H₅N₃O₂)]·H₂O}_n, (1), and poly[2‐amino‐3‐carboxypyrazin‐1‐ium [(3‐aminopyrazine‐2‐carboxylato‐κ²N¹,O)di‐μ‐chlorido‐cadmium(II)] monohydrate], {(C₅H₆N₃O₂)[Cd(C₅H₄N₃O₂)Cl₂]·H₂O}_n, (2), have been synthesized from the reaction of cadmium(II) chloride and 3‐aminopyrazine‐2‐carboxylic acid (Hapca) under mild conditions in acidic media. The two coordination polymers have been characterized by single‐crystal X‐ray diffraction and show chloride‐bridged zigzag chains with octahedrally coordinated metal ions, where Hapca acts as a bidentate ligand via the π‐conjugated N atom and a carboxylate O atom. The chains are further interconnected via noncovalent interactions into three‐dimensional supramolecular networks. The dominant H…O and H…Cl interactions for both compounds were quantified using Hirshfeld surface analysis. The thermal stability and topological analysis of the two‐dimensional networks of (1) and (2) are also discussed.     

Influence of structural variation of salamo‐based ligand on supramolecular architectures,Hirshfeld analyses,and fluorescence properties of new tetranuclear NiII complexes

Two new tetranuclear Ni^II complexes, [Ni₄(L¹)₂(N₃)₄(MeOH)₂]·CH₃COCH₃ (1) and [Ni₄(L²)₂(N₃)₄(MeOH)₂]·4CH₃COCH₃ (2) , were synthesized using NiCl₂·6H₂O, NaN₃, and asymmetric salamo‐based ligands H₂L¹ and H₂L², respectively. The structural characterization was made by elemental analyses, infrared (IR) and ultraviolet‐visible (UV‐vis) spectra, and X‐ray diffraction analyses. The results of X‐ray diffraction analyses show that the Ni^II atoms in complexes 1 and 2 are distorted octahedral geometries. Interestingly, the degree of distortion of the ligands in complexes 1 and 2 is different, which indicates that the interaction of Ni^II ions on different ligands is different. Meanwhile, the investigation of molecular packing by employing the Hirshfeld surface analysis exhibits that the percentages of C–H/H–C, O–H/H–O, and H–H/H–H contacts of the complex 1 (or 2 ) are calculated to be 17.7%, 7.9%, and 53.7% (or 18.8%, 13.8%, and 52.5%), respectively, where the H–H/H–H contacts have the characteristics of strong contacts whereas the O–H/H–O hydrogen bonds are considerably weak, and the studies on fluorescence properties further confirm the Ni^II atoms have different binding abilities to the different ligands.     

Two hydrazones derived from 1‐aryl‐3‐(p‐substituted phenyl)prop‐2‐en‐1‐one: synthesis,crystal structure,Hirshfeld surface analysis and in vitro biological properties

Two chalcones were synthesized by the aldolic condensation of enolizable aromatic ketones with substituted benzaldehydes under Claisen–Schmidt reaction conditions and then treated with 2,4‐dinitrophenylhydrazine to yield their corresponding hydrazones. The two (E,Z)‐2,4‐dinitrophenylhydrazone structures, namely (Z)‐1‐(2,4‐dinitrophenyl)‐2‐[(E)‐3‐(4‐methylphenyl)‐1‐phenylallylidene]hydrazine, C₂₂H₁₈N₄O₄, ( H1 ), and (Z)‐1‐[(E)‐3‐(4‐chlorophenyl)‐1‐(naphthalen‐1‐yl)allylidene]‐2‐(2,4‐dinitrophenyl)hydrazine, C₂₅H₁₇ClN₄O₄, ( H2 ), were isolated by recrystallization and characterized by FT–IR, UV–Vis, single‐crystal and powder X‐ray diffraction methods. The UV–Vis spectra of the hydrazones have been studied in two organic solvents of different polarity. It was found that ( H2 ) has a molar extinction coefficient larger than 40000. Single‐crystal X‐ray diffraction analysis reveals that the molecular zigzag chains of ( H1 ) and ( H2 ) are interconnected through noncovalent contacts. A quantitative analysis of the intermolecular interactions in the crystal structures has been performed using Hirshfeld surface analysis. All the synthesized chalcones and hydrazones were evaluated for their antibacterial and antioxidant activities. Results indicate that the studied compounds show significant activity against Gram negative Escherichia coli strain and the chalcone 3‐(4‐methylphenyl)‐1‐phenylprop‐2‐en‐1‐one, ( C1 ), was the most effective. In addition, only hydrazone ( H1 ) displayed a moderate DPPH (2,2‐diphenyl‐1‐picryl hydrazyl) scavenging efficiency.     

Mononuclear Co(III), Ni(II) and Cu(II) complexes of tridentate di‐tert‐butylphenylhydrazone: Synthesis,characterization, X‐ray crystal structures,Hirshfeld surface analysis,molecular docking and in vivo anti‐inflammatory activity

A new hydrazone (LH₂) derived from the condensation of 2‐(4‐fluorobenzamido)benzohydrazide with 3,5‐di‐tert‐butyl‐2‐hydroxybenzaldehyde was used to synthesize Co(III), Ni(II) and Cu(II) complexes. These were characterized using various physicochemical, thermal, spectroscopic and single‐crystal X‐ray diffraction techniques. All the complexes crystallize in a monoclinic crystal system with P2₁/n space group and Z = 4. Structural studies of [Co(L)(LH)]?H₂O indicate the presence of both amido and imidol tautomeric forms of the ligand, resulting in a distorted octahedral geometry around the Co(III) ion. On the other hand, in the [Ni(L)(DMF)] and [Cu(L)(H₂O)] complexes, the ligand coordinates to the metal through imidol form resulting in distorted square planar geometry, in which the fourth position is occupied by the oxygen of coordinated DMF in [Ni(L)(DMF)] and by a water molecule in [Cu(L)(H₂O)]. Hirshfeld surface calculations were performed to explore hydrogen bonding and C―H???π interactions. Molecular docking studies were carried out to study the interaction between the synthesized compounds and proteins (cyclooxygenase‐2 and 5‐lipoxygenase). The complexes along with the parent ligand were screened for their in vivo anti‐inflammatory activity, using the carrageenan‐induced rat paw oedema method. The complexes show significant anti‐inflammatory potencies.     

Concomitant polymorphism in an organometallic ruthenium(II) complex with an N,N′‐donor ligand

The simultaneous crystallization of different polymorphs, i.e. concomitant polymorphism, is a phenomenon which, when properly recognized and studied, can provide useful information for a variety of disciplines. It is rare for ruthenium complexes, although it has been observed. In the synthesis of the ruthenium(II) complex chlorido(η⁶‐p‐cymene)(dimethyl 2,2′‐bypyridine‐4,5‐dicarboxylate‐κ²N,N′)ruthenium(II) hexafluoridophosphate, [RuCl(C₁₀H₁₄)(C₁₄H₁₂N₂O₄)]PF₆, concomitant polymorphs were crystallized under the same conditions. The colour of both crystals was orange, but the shapes, as well as the orientation of the p‐cymene and methoxycarbonyl groups, were different. The crystal structures of both isomers show approximately the same bond lengths. In the asymmetric unit, there is one cation and one anion. Due to the absence of strong hydrogen bonds, only weak intermolecular interactions were observed. The Hirshfeld surface and two‐dimensional fingerprint plots of both isomers satisfactorily explain the difference in the melting points.     

Crystal structures and Hirshfeld surface analysis of transition‐metal complexes of 1,3‐azolecarboxylic acids

The crystal structures of five new transition‐metal complexes synthesized using thiazole‐2‐carboxylic acid (2‐Htza), imidazole‐2‐carboxylic acid (2‐H₂ima) or 1,3‐oxazole‐4‐carboxylic acid (4‐Hoxa), namely diaquabis(thiazole‐2‐carboxylato‐κ²N,O)cobalt(II), [Co(C₄H₂NO₂S)₂(H₂O)₂], 1 , diaquabis(thiazole‐2‐carboxylato‐κ²N,O)nickel(II), [Ni(C₄H₂NO₂S)₂(H₂O)₂], 2 , diaquabis(thiazole‐2‐carboxylato‐κ²N,O)cadmium(II), [Cd(C₄H₂NO₂S)₂(H₂O)₂], 3 , diaquabis(1H‐imidazole‐2‐carboxylato‐κ²N³,O)cobalt(II), [Co(C₄H₂N₂O₂)₂(H₂O)₂], 4 , and diaquabis(1,3‐oxazole‐4‐carboxylato‐κ²N,O⁴)cobalt(II), [Co(C₄H₂NO₃)₂(H₂O)₂], 5 , are reported. The influence of the nature of the heteroatom and the position of the carboxyl group in relation to the heteroatom on the self‐assembly process are discussed based upon Hirshfeld surface analysis and used to explain the observed differences in the single‐crystal structures and the supramolecular frameworks and topologies of complexes 1 – 5 .     

A new nano‐sized mononuclear Cu (II) complex with N,N‐donor Schiff base ligands: sonochemical synthesis,characterization, molecular modeling and biological activity

A new, simple Cu²⁺ nano‐structure Schiff base complex in methanol medium has been synthesized by the ultrasonic method. Structure of the compound was confirmed by FT‐IR, GC‐Mass and other spectroscopic techniques. The copper oxide (CuO) was achieved from the copper nano‐structure Schiff base complex as the raw material after calcination for 3 hr at 600 °C. According to results Cu²⁺ gives a complex with mole ratio 1:2 of metal to ligand (ML₂) with Schiff base which a distorted square planer is the most probable geometry for it. The calculations results from XRD patterns propose the nano‐sized complexes. The SEM images show morphology of both the copper complex and the CuO powder were plate‐like. The metal chelates of Cu²⁺ in two states of bulk and nano have been screened for their in vitro antibacterial activity against four bacteria, gram‐positive (Staphylococcus aureus) and gram‐negative (Escherichia coli) and three strains of fungus (Aspergillus flavus). The nano metal chelates were shown to possess more antibacterial activity than the bulk chelate. Finally, the empirical parameters of Schiff base compounds showed a good agreement with theoretical ones.     

Structure,atomic Hirshfeld surface,spectroscopic studies and magnetic and dielectric properties of new mixed solid solution (NH4)2Mn0.17Cu0.83Cl4⋅2H2O

The tetrachlorocupratmanganate dehydrate (NH₄)₂Mn_0.17Cu_0.83Cl₄?2H₂O has been prepared and characterized using various physicochemical techniques including Fourier transform infrared and Raman spectroscopies, differential scanning calorimetry and dielectric and magnetic measurements. A preliminary single‐crystal X‐ray diffraction structural analysis reveals that the title compound belongs to the tetragonal system with P4₍₂₎/mnm space group. The unit cell dimensions are: a = b = 7.5817(2), c = 7.9312(2) Å, with Z = 2. Its crystal structure was determined and refined down to R = 2%. The structure of this compound consists of discrete [Cu/MnCl₄?2H₂O]^2? octahedra interleaved with alkali cations. The cohesion and stabilization of the structure are provided by hydrogen bond interactions (N─H…Cl and O─H…Cl) between [NH₄]⁺ cation and [Cu/MnCl₄?2H₂O]^2? anion. Hirshfeld surface analysis has been performed to explore the behaviour of these weak interactions. Dielectric measurements confirm the transition temperatures determined using differential scanning calorimetry. The temperature dependence of the magnetic susceptibility was measured in the temperature range 10–300 K at various magnetic field intensities. Magnetic measurements reveal the occurrence of weak ferromagnetic behaviour at low temperature (T_c = 12 K). The ferromagnetic ordering is further confirmed by the presence of hysteresis loops.     

DNA interaction,cytotoxicity and molecular structure of cobalt complex of 4‐amino‐N‐(6‐chloropyridazin‐3‐yl)benzene sulfonamide in the presence of secondary ligand pyridine

Novel cobalt complex of 4‐amino‐N‐(6‐chloropyridazin‐3‐yl)benzene sulfonamide (sulfachloropyridazine) has been synthesized and characterized by elemental analysis, FT‐IR spectroscopy and magnetic susceptibility (VSM). Cobalt complex of Sulfachloropyridazine (Co‐SCP) crystallized in monoclinic space group P2₁/n with Z = 4. The structure is solved by direct method and refined to R = 0.099 for 4720 reflections with I ?4σ(I). The results of FT‐IR spectra suggest the binding of cobalt atom to the sulfonamide ligand which is in agreement with the crystal structure determination. In crystal structure, molecule is linked via, C‐H … π, C‐Cl … π and π … π intermolecular interactions. The computational studies like the optimization energy and root means square deviation compare with single crystal structure, frontier molecular orbital (Homo‐Lumo energy) and binding energy of the Co‐SCP has been carried out using DFT/B3LYP level of theory in gaseous phase. Hirshfeld surfaces and the 2D‐fingerprint analysis are performed to study the nature of interactions and their measurable contributions towards crystal packing. The interaction of the complex with DNA is investigated using viscosity measurement and absorption titration studies. The result shows the complex bind to DNA with intercalative mode with high DNA‐binding constant (K_b). Also, in vivo and in vitro cytotoxic studies are performed using S. pombe cells and brine shrimp lethality bioassay. DNA‐cleavage study shows better cleaving ability of the complex.     

Invariom‐model refinement and Hirshfeld surface analysis of well‐ordered solvent‐free dibenzo‐21‐crown‐7

Crown ethers and their supramolecular derivatives are well‐known chelators and scavengers for a variety of cations, most notably heavier alkali and alkaline‐earth ions. Although they are widely used in synthetic chemistry, available crystal structures of uncoordinated and solvent‐free crown ethers regularly suffer from disorder. In this study, we present the X‐ray crystal structure analysis of well‐ordered solvent‐free crystals of dibenzo‐21‐crown‐7 (systematic name: dibenzo[b ,k ]‐1,4,7,10,13,16,19‐heptaoxacycloheneicosa‐2,11‐diene, C₂₂H₂₈O₇). Because of the quality of the crystal and diffraction data, we have chosen invarioms, in addition to standard independent spherical atoms, for modelling and briefly discuss the different refinement results. The electrostatic potential, which is directly deducible from the invariom model, and the Hirshfeld surface are analysed and complemented with interaction‐energy computations to characterize intermolecular contacts. The boat‐like molecules stack along the a axis and are arranged as dimers of chains, which assemble as rows to form a three‐dimensional structure. Dispersive C—H…H—C and C—H…π interactions dominate, but nonclassical hydrogen bonds are present and reflect the overall rather weak electrostatic influence. A fingerprint plot of the Hirshfeld surface summarizes and visualizes the intermolecular interactions. The insight gained into the crystal structure of dibenzo‐21‐crown‐7 not only demonstrates the power of invariom refinement, Hirshfeld surface analysis and interaction‐energy computation, but also hints at favourable conditions for crystallizing solvent‐free crown ethers.     

Three zinc(II) and cadmium(II) complexes containing 4‐amino‐3,5‐bis(pyridin‐2‐yl)‐1,2,4‐triazole and polynitrile ligands: synthesis,molecular and supramolecular structures,and photoluminescence properties

Three photoluminescent complexes containing either Zn^II or Cd^II have been synthesized and their structures determined. Bis[4‐amino‐3,5‐bis(pyridin‐2‐yl)‐1,2,4‐triazole‐κ²N ¹,N ⁵]bis(dicyanamido‐κN ¹)zinc(II), [Zn(C₁₂H₁₀N₆)₂(C₂N₃)₂], (I), bis[4‐amino‐3,5‐bis(pyridin‐2‐yl)‐1,2,4‐triazole‐κ²N ¹,N ⁵]bis(dicyanamido‐κN ¹)cadmium(II), [Cd(C₁₂H₁₀N₆)₂(C₂N₃)₂], (II), and bis[4‐amino‐3,5‐bis(pyridin‐2‐yl)‐1,2,4‐triazole‐κ²N ¹,N ⁵]bis(tricyanomethanido‐κN ¹)cadmium(II), [Cd(C₁₂H₁₀N₆)₂(C₄N₃)₂], (III), all crystallize in the space group P , with the metal centres lying on centres of inversion, but neither analogues (I) and (II) nor Cd^II complexes (II) and (III) are isomorphous. A combination of N—H…N and C—H…N hydrogen bonds and π–π stacking interactions generates three‐dimensional framework structures in (I) and (II), and a sheet structure in (III). The photoluminescence spectra of (I)–(III) indicate that the energies of the π–π* transitions in the coordinated triazole ligand are modified by minor changes of the ligand geometry associated with coordination to the metal centres.     

Exploiting the versatility of pyridyl ligands for the preparation of diorganotin (IV) adducts: spectral,crystallographic and Hirshfeld surface analysis studies

Diorganotin (IV) complexes SnR₂X₂ (R = Me, Ph; X = Cl, NCS) form a series of versatile complexes when react with bidentate substituted pyridyl ligands. The reaction of dimethyltin dichloride with 5,5′‐dimethyl‐2,2′‐bipyridine (5,5′‐Me₂bpy) resulted in the formation of [SnMe₂Cl₂(5,5′‐Me₂bpy)] ( 1 ). Moreover, the reaction of SnMe₂(NSC)₂ with 4,4′‐di‐tert‐butyl‐2,2′‐bipyridine (bu₂bpy), 1,10‐phenanthroline (phen) and 4,7‐diphenyl‐1,10‐phenanthroline (bphen) affords the hexa‐coordinated complexes [SnMe₂(NCS)₂(bu₂bpy)] ( 2 ), [SnMe₂(NCS)₂(phen)] ( 3 ) and [SnMe₂(NCS)₂(bphen)] ( 4 ), respectively. The resulting complexes have been characterized using elemental analysis, IR, multinuclear NMR (¹H, ¹³C, ¹¹⁹Sn) and DEPT‐135^° NMR spectroscopy. On the other hand, the reaction of diphenyltin dichloride with 2,2′‐biquinoline (biq) and 4,7‐phenantroline (4,7‐phen) led to the formation of polymeric complexes of [SnPh₂Cl₂(4,7‐phen)]_n ( 5 ) and [SnPh₂Cl₂(biq)]_n ( 6 ). The NMR spectra, however, reveal the ligand lability in solution and suggest a coordination number of 5 . The X‐ray crystal structures of complexes [SnMe₂Cl₂(5,5′‐Me₂bpy)] ( 1 ), [SnMe₂(NCS)₂(bu₂bpy)] ( 2 ) and [SnMe₂(NCS)₂(bphen)] ( 4 ) have been determined which reveal that the geometry around the tin atom is distorted octahedral with trans‐[SnMe₂] configuration. Interestingly, the crystal structure of (H₂biq)₂[SnPh₂Cl₄]?2CHCl₃ ( 7 ) was characterized by X‐ray crystallography from a chloroform solution of [SnPh₂Cl₂(biq)]_n ( 6 ) indicating the formation of doubly protonated [H₂biq]⁺ and [Ph₂SnCl₄]^2? which are stabilized by a network of hydrogen bonds with a feature of trans‐[SnPh₂]. The 3D Hirshfeld surface analysis and 2D fingerprint maps were used for quantitative mapping out of the intermolecular interactions for 1 , 2 , 4 and 7 which show the presence of π‐π and hydrogen bonding interactions which are associated between donor and acceptor atoms (N, S, Cl) in the solid state.     

Synthesis,crystal structures,spectral FT‐IR,NMR and UV–Vis investigations and Hirshfeld surface analysis of two new 2‐hydroxyethyl‐substituted N‐heterocyclic carbene precursors

This study discusses the synthesis of two new 2‐hydroxyethyl substituted N‐heterocyclic carbene (NHC) precursors. The NHC precursors were prepared from 1‐(alkyl/aryl)benzimidazole and alkyl halides. They were characterized using ¹H NMR, ¹³C NMR, FT‐IR, UV–Vis spectroscopy, and elemental analysis techniques. Molecular and crystal structures of 1 and 2 were determined using the single‐crystal X‐ray diffraction method. Crystal structure of the compounds features NHC precursors and chloride anions. Additionally in 2 , the asymmetric unit has a water molecule, which forms a tetrameric chloride‐hydrate assembly with the chloride anion. The chloride anions play an important role in the stabilization of crystal structures to form a two‐dimensional supramolecular architecture. The 3D Hirshfeld surface and the associated 2D fingerprint plots were also drawn to gain insights into the behavior of the interactions in the compounds.     

A new six-coordinate organotin(IV) complex of OP[NC5H10]3: A comparison with an analogous five-coordinate complex by means of X-ray crystallography,Hirshfeld surface analysis and DFT calculations

A new six-coordinate organotin(IV)-phosphoric triamide complex of OP[NC₅H₁₀]₃ = OP was synthesized ([Cl₂Sn(CH₃)₂(OP)₂], 1) and characterized by X-ray crystallography and spectroscopic methods (FT-IR, UV–Vis, and ¹H/¹³C/³¹P-NMR). The crystal structures of 1 and the analogous previously reported five-coordinate complex [Cl₂Sn(CH₃)₂(OP)] (IZOVIE) were compared on a structural level and by computational means using Hirshfeld surface analysis, density functional theory calculations and the atom in molecule method. The investigation of intermolecular interactions in the crystal structures of the two complexes by the Hirshfeld surface method indicates that in the absence of normal hydrogen bonds, the chlorine-based interactions H?Cl/Cl?H (for 1 and IZOVIE) and Cl?Sn/Sn?Cl (for IZOVIE) play a determinant role in the molecular assemblies. However, the prominent contacts are of H?H type. From calculated electronic parameters such as bond order, Mulliken charge and electron delocalization energy, it was found that the Sn-OP contact has a lower strength in IZOVIE than in 1, suggesting more ionic character of the metal-oxygen contact in five-coordinate complex IZOVIE. Furthermore, we discuss the similarities and differences of the two complexes 1 and IZOVIE derived from the same ligand OP by density functional theory calculations to present an insight into the organotin(IV)-phosphoric triamide coordination chemistry affected by different geometries and coordination numbers.     

Synthesis,structural characterization,EPR spectroscopy and Hirshfeld surface analysis of a novel Cu2+‐doped 3,14‐diethyl‐2,13‐diaza‐6,17‐diazoniatricyclo[16.4.0.07,12]docosane bis(perchlorate)

Cyclam derivatives and their metal complexes have been found to exhibit an anti‐HIV effect and stimulate the activity of stem cells from bone marrow. The strength of their binding to the CXCR4 receptor correlates with anti‐HIV and stem‐cell activities. Knowledge of the conformation and crystal packing of various macrocyclic metal complexes has become important in developing new effective anti‐HIV drugs. The synthesis and preparation of single crystals of a new Cu²⁺‐doped macrocyclic compound, (3,14‐diethyl‐2,6,13,17‐tetraazatricyclo[16.4.0.0^7,12]docosane)copper(II) bis(perchlorate)–3,14‐diethyl‐2,13‐diaza‐6,17‐diazoniatricyclo[16.4.0.0^7,12]docosane bis(perchlorate) (0.69/0.31), {[Cu(C₂₂H₄₄N₄)](ClO₄)₂}_0.69·(C₂₂H₄₆N₄²⁺·2ClO₄^?)_0.31, is reported. Characterization by X‐ray diffraction analysis shows that the asymmetric unit contains half of a centrosymmetric molecule. The macrocyclic ligand in the compound adopts the most stable trans‐III conformation. The Cu—N distances of 2.015 (3) and 2.047 (3) Å are normal, but the long axial Cu—O bond of 2.795 (3) Å may be due to a combination of the Jahn–Teller effect and the strong in‐plane ligand field. The crystal structure is stabilized by hydrogen bonding between secondary N—H groups, the N atoms of the macrocycle and the O atoms of the perchlorate anions. Hirshfeld surface analysis with 2D (two‐dimensional) fingerprint plots indicates that the main contributions to the crystal packing are from H…H (58.0%) and H…O/O…H (41.9%) interactions. Electron paramagnetic resonance (EPR) properties are also described.