Two-dimensional Supramolecular Structure Research Articles

9,10-Bis(iodo-ethyn-yl)anthracene.

The title compound, C18H8I2, is an ethynyl-substituted anthracene. The C-C-I bond angles deviate from 180°, being affected by inter-molecular I⋯π inter-actions. These inter-actions form a two-dimensional supra-molecular structure further supported by offset π-π stacking of neighboring anthracene moieties.

The first salamo-type mixed-ligand Cu(II) coordination polymer: Synthesis, crystal structure and theoretical studies

In this work, a copper(II) coordination polymer [Cu2(L1)(L2)(NO3)]n·nCH3OH (Cu(II)-CP) with different structures of mixed salamo-type ligands was constructed for the first time. Single crystal X-ray diffraction analysis showed that the Cu(II)-CP asymmetric unit consists of two copper(II) atoms, fully deprotonated (L1)−, (L2)2− ligand units, one NO3− anion and one molecule of crystallized methanol. The two metallized ligand units are bridged by two oxygen atoms of NO3− to form unique mixed-ligand copper(II) coordination polymer. In addition, the six coordination atoms around the two Cu(II) atoms are all arranged in a distorted octahedral geometry. In the molecular structure of Cu(II)-CP, neighbouring molecules interact through intermolecular hydrogen bonds to form a two-dimensional supramolecular structure. Intermolecular interactions and molecular stability were further investigated by Hirshfeld surface analysis and other theoretical calculations. Finally, the antimicrobial activities of both ligands and Cu(II)-CP were investigated and found to exhibit excellent antibacterial activities.

Synthesis, characterization, crystal structures and thermochemical properties of five lanthanide complexes with mononuclear and binuclear structures

Five new lanthanide complexes were synthesized by two different experimental methods: two mononuclear complexes and three binuclear complexes. Their chemical formula is: [Gd(2-Cl-4-FBA)3(terpy)H2O]1.5H2O(1); [Dy(2-Cl-4-FBA)3(terpy)H2O]·0.5H2O(2)) (2-Cl-4-FBA = 2-chloro- 4-fluorobenzoate,terpy = 2,2′:6′,2″-terpyridine); [Ln(3,4-DFBA)3(5,5′-DM-2,2′-bipy)(H2O)]2(Ln = Pr(3),Er(4);[Ln(3,4-DFBA)3(5,5′-DM-2,2′-bipy)]2(Ln = Ho(5)) (3,4-DFBA = 3, 4-difluorobenzoate,5,5′-DM-2,2′-bipy = 5,5′-dimethyl-2,2′-bipyridine). A series of characterization and properties of the complexes were studied, such as elemental analysis, single crystal X-ray diffraction, thermogravimetric analysis, fluorescence properties and so on. The coordination number of complexes 1–2 is 9, showing a muffin geometry. The results show that complex 1–5 crystallized in the triclinic system and space group Pī. Complexes 1 and 2 are isostructural except for the number of free water molecules. Complexes 3–5 are binuclear molecules with different structures. Although the structures of the five complexes are different, they all form one and two-dimensional supramolecular structures along a chain and a plane. The thermal decomposition mechanism of complexes 1–5 was studied by synchronous thermal analyzer infrared spectroscopy (TG/DSC-FTIR). The results show that the coordination water, neutral ligand and acidic ligand are lost in turn when the complex undergoes thermal decomposition. And the three-dimensional infrared images of gas escaping during the thermogravimetric process were analyzed. In addition, the solid state fluorescence spectra of complex 2 was measured and the results showed that the characteristic fluorescence of Dy(III) ion was emitted.

Unusual fluorescence behavior of first 3d-3d′ heterobimetallic [Cu(II)2Mn(II)] complex bearing a bis(salamo)-based ligand

• The first 3d-3d′ heterobimetallic [Cu(II) 2 Mn(II)] bis(salamo)-based complex was synthesized and characterized structurally. • The different natures of the N 2 O 2 and O 6 sites of H 4 L lead to the site‐selective introduction of two various metal(II) atoms. • Unusual fluorescence behavior of the [Cu(II) 2 Mn(II)] complex was reported. The first 3d-3d′ heterobimetallic [Cu(II) 2 Mn(II)] complex, [Cu 2 Mn(L)( µ 2 -NO 3 ) 2 ] was reported, and formed by an acyclic tricompartmental bis(salamo)-based ligand H 4 L and different metal salts. Its structure was characterized by physicochemical and spectroscopic methods. The ligand H 4 L has two identical N 2 O 2 sites and one O 6 site separated by phenoxy groups. Two penta-coordinate Cu(II) atoms and one octa-coordinated Mn(II) atom are located respectively in these two different coordination environments. Through the analysis of the Hirshfeld surfaces of the [Cu(II) 2 Mn(II)] complex, the intermolecular interactions involved in the crystal structure can be shown, and the corresponding quantitative information is given by fingerprint. The [Cu(II) 2 Mn(II)] complex units are combined by intermolecular C-H•••O hydrogen bonds to form a two-dimensional supramolecular structure. Unusual fluorescence behavior of the [Cu(II) 2 Mn(II)] complex was further studied.

Slow Phase Transition-Induced Scan Rate Dependence of Spin Crossover in a Two-Dimensional Supramolecular Fe(III) Complex

Slow Phase Transition-Induced Scan Rate Dependence of Spin Crossover in a Two-Dimensional Supramolecular Fe(III) Complex

4,4-Nitrophenoxyaniline derived Azo ester: Structural elucidation, DFT simulation, and DNA interactional studies via wet and in silico methods

A new ester namely,1-((4-(4-nitrophenoxy)phenyl)diazenyl)biphenyl benzoate, has been synthesized by esterification reaction between reported nitro terminated azo alcohol and benzoyl chloride. Complete structural elucidation of the synthesized ester was done by different spectroscopic techniques including (FT-IR), (Proton and Carbon-13 NMR), (UV/VIS) spectroscopy, and single-crystal XRD analysis and cyclic voltammetry. XRD structural elucidation revealed the ester 1a to be in Triclinic crystal system with P-1 space groups, showing two-dimensional supramolecular structure, involving only one intermolecular interaction between O4-O9…H9. DFT simulations were also performed to illustrate structural ramification of synthesized ester.Further, Drug DNA interaction was used to determine the biological significance of the produced ester. UV–VIS spectroscopy, hydrodynamic measurement, and molecular docking were used to determine the preferred binding mode of interaction of the synthesized ester with Salmon Sperm (SS) DNA and found that molecule interacts in groove binding fashion with DNA molecule. 2021 Elsevier Ltd. All rights reserved.

Crystal structure, thin film preparation, theoretical and experimental study the nonlinear optical properties of a novel copper complex

A novel metal-organic complex: bis(imidazole)-bis(isothiocyanato)-copper(II) ((C3H4N2)2Cu(NCS)2) has been synthesized, its crystal structure has been determined by means of X-ray single crystal diffraction. The copper(II) ion is four coordinated with the four nitrogen atoms in a square planar environment, short contacts of C-H⋯C and S‾⋯Cu2+ leading to the formation of a two-dimensional (2D) supramolecular plane structure parallel ab plane. Its crystal thin film were prepared using in-situ crystallization methods on quartz substrates. The surface morphology of the thin film were studied by atomic force microscopy (AFM). The nonlinear optical (NLO) properties of the thin film were investigated by using closed aperture Z-scan technique with 20 picosecond (ps) pulses at wavelength 532 nm. Time-dependent density-functional theory (TDDFT) with the basis set LanL2DZ were used in theoretically computing the frontier molecular orbitals (FMO) and molecule’s second hyperpolarizability γ value.

An insight into non-covalent interactions in the tetraphenylarsonium dithiophosphates: Synthesis, DFT and Hirshfeld surface analysis

Three tetraphenylarsonium dithiophosphate salts [Ph4As]+[S2P(OAr)2]−, where Ar = 2,4-(CH3)2C6H3 (1), 3,5-(CH3)2C6H3 (2), {4-(CH3)3C}C6H4 (3), were crystallized in the monoclinic space group P21 (1), triclinic space group P¯1 (2) and monoclinic space group P21/c (3), respectively. These salts are stabilized by various non-covalent interactions resulting in the extension of their molecular structure along different axis. The cationic and anionic species are interconnected by various C—H•••X, C—H•••π (X = O, S) interactions leading the molecules as one-dimensional and two-dimensional supramolecular structures. A thorough Hirshfeld surface analysis elegantly quantifies the various non-covalent interactions present within the molecules. This analysis reveals that the main contributions in all the three salts are because of H…H and C…H/H…C interactions that represent 82.1%, 82.9% and 84.1% of the total contribution to the Hirshfeld surface for 1, 2 and 3, respectively. Further, the coordinates were optimized by DFT calculations with B3LYP hybrid functional along with LANL2DZ basis set. Experimental values of bond lengths and bond angles are in good agreement with the optimized structural parameters. HOMO-LUMO of the molecules were calculated using corresponding methods with the same basis set. Other computational data pertaining to chemical reactivity have indicated potential sites for nucleophilic and eletrophilic attack in the molecules.

Synthesis, structural topology, DFT, and photoluminescence properties of Sm(III) and octacyanomolybdate(V) building-block-based 1-D chain complex

A new one-dimensional cyanide-based coordination polymer comprising Sm(III) and octacyanomolybdate(V) building blocks was prepared and characterized through single-crystal X-ray diffraction and elemental analyses. The new compound consisted of one-dimensional chains of [Sm(terpy)(DMF)4] [Mo(CN)8] (complex 1) (terpy: 2,2′:6′,2′′-terpyridine; DMF: N,N-dimethylformamide), where each Mo(CN)8 entity served as a bis-monodentate bridging ligand of two Sm(III) ions alternately through two of its six cyanide groups at cis positions. The corresponding chains were formed by hydrogen bonds, and van der Waals interactions to form a two-dimensional supramolecular structure that stabilized the entire molecule. Considering all the intermolecular interactions during the simplification procedure, we obtained a description of the molecular packing. The calculation results indicated that the underlying net corresponds to a new topology with the following point symbol {337.468.530.6}{38.42}. Density functional theory studies were also performed to elucidate the electronic structure within the entire complex. The good luminescence of the complex makes it a suitable material for construction of photoluminescent materials, to explore the intrinsic optical properties of lanthanides, and in sensing for detection of different hazardous/explosive materials.

Synthesis, antiproliferative activities, and DNA binding of coumarin‐3‐formamido derivatives

Ten coumarin-3-formamido derivatives, N-benzyl-coumarin-3-carboxamide (2), N-fluorobenzyl-coumarin-3-carboxamide (3-5), N-methoxybenzyl-coumarin-3-carboxamide (6-8), N-((1-methyl-1H-imidazol-5-yl)methyl)-coumarin-3-carboxamide (9), N-(thiophen-2-ylmethyl)-coumarin-3-carboxamide (10), and N-(furan-2-ylmethyl)-coumarin-3-carboxamide (11), were synthesized and characterized. Compound 5 crystallizes in a monoclinic system P21 /c space group with four chemical formulas in a unit cell; molecules of compound 5 are self-assembled into a two-dimensional supramolecular structure by intermolecular hydrogen bonds and C⋯C π stacking. The potential anticancer effects of these compounds on HeLa (cervical carcinoma), MCF-7 (breast), A549 (lung), HepG2 (liver), and human umbilical vein (HUVEC) cells were examined. Compared with compounds 1-8 and 10-11, compound 9 exhibits potent in vitro cytotoxicity against HeLa cells and lower cytotoxicity against normal cells. Therefore, further in-depth investigations of compound 9 were performed. Absorption titration experiments and fluorescence spectroscopy studies suggested that compound 9 binds to DNA through the intercalation mode.

Excellent catalytic activity of ethylenediamine stabilised oxalate ligated aluminium coordination complex for synthesis of novel benzoquinolines

Two-dimensional supramolecular structure of oxalate ligated Al(III) coordination complex, (C2H10N2)2.[Al2(µ-O2)(oxalate)4]∙2H2O (Al-Ox) was synthesised hydrothermally and determined the structural features with single-crystal X-ray diffraction studies. Unique oxo bridged dinuclear Al(III) clusters were established and each Al(III) atom bonded with two units of oxalate ligand. In the dinuclear Al(III) structure, two Al(III) atoms were separated with a bond distance of 2.8702 Å. Unsaturated metal centres creation upon activation acts as Lewis acid sites and ethylenediamine with a strong basic character in the structure remarkably facilitate an efficient and economic strategy for better organic transformations. The Lewis acid-base character catalytic efficacy of the complex is explored in the tandem multi-component synthesis of benzoquinoline-2-carbonitrile moieties. The synergy between the exceptional Lewis acidic and basic properties of Al-Ox contributed to its excellent catalytic activity in the generation of five new benzoquinoline-2-carbonitriles in impressive yields (92–96%) in short reaction time (ca.15 min) in a simple one-pot protocol, in ethanol. Recyclability with consistent activity (>5 times) is the added advantage.

Selenium-containing core-expanded naphthalene diimides for high performance n-type organic semiconductors

The incorporation of heavy atoms into molecular backbone is an extremely straightforward strategy for fine-tuning the optoelectronic properties of organic semiconductors. However, it is rarely studied in n-type small molecules. Herein, by selenium substitution of NDI3HU-DTYM2, two Se-decorated core-expanded naphthalene diimides (NDI) derivatives DTYM-NDI3HU-DSYM ( 1 ) and NDI3HU-DSYM2 ( 2 ) were synthesized. In comparison with the reference S-containing compound NDI3HU-DTYM2, the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of 1 and 2 were fine-tuned with ∆HOMO of about 0.2 eV, ∆LUMO of 0.1 eV and the narrowed HOMO-LUMO gaps. More surprisingly, the as-spun organic thin film transistors (OTFTs) based on 1 and 2 both showed µ e,sat values as high as 1.0 cm2 V−1 s−1, which are 2-fold higher than that of NDI3HU-DTYM2 with the same device structure and measurement conditions. In addition, the single crystal OFET devices based on Se-containing compound NDI2BO-DSYM2 showed a high µ e,sat value of 1.30 cm2 V−1 s−1. The molecular packing of NDI2BO-DSYM2 in single crystals (two-dimensional supramolecular structure formed by intermolecular Se···Se interactions) is quite different from that of a S-containing compound NDI-DTYM2 (one dimensional supramolecular structure formed by intermolecular π-π stacking). Therefore, the Se substitution can cause dramatic change about molecular stacking model, giving rise to high n-type OTFT performance. Our results demonstrated an effective strategy of the heavy atom effect for designing novel organic semiconductors.

A series of lanthanide complexes with 2,4-dimethylbenzoic acid and 2,2:6′,2″-terpyridine: Supramolecular structures, thermal decomposition mechanism and photoluminescence

Six new binuclear lanthanide complexes [Ln(2,4-DMBA)3(terpy)(H2O)]2 (Ln = Eu (1), La (2), Pr (3), Nd (4), Sm (5), Gd (6)) (2,4-DMBA = 2,4-dimethylbenzoate; terpy = 2,2:6′,2″-terpyridine) and four mononuclear complexes [Ln(2,4-DMBA)3(terpy)(H2O)] (Ln = Dy (7), Ho (8), Er (9), Tb (10)) have been synthesized. Complexes 1–6 and 7–10 are isomorphous, adopting interesting structures. In the structures of complexes 1–6, two nine-coordinated Ln(III) centers are linked by two 2,4-DMBA ligands in bridging mode. The other two 2,4-DMBA ligands coordinate with one Ln(III) cation in monodentate and chelating modes. In the structures of complexes 7–10, the Ln(III) center is eight-coordinated. Complexes 1–6 and 7–10 can each aggregate to form one-dimensional and two-dimensional supramolecular structures. Thermal decomposition of complexes 1–10 has been investigated by TG-DSC/FTIR. Interestingly, all of the complexes exhibit a similar three-step decomposition process. The Eu(III) and Tb(III) complexes show strong red and green visible light luminescence. Finally, fluorescence lifetimes and intrinsic quantum yields have been calculated for complexes 1 and 10.

Two new cadmium(II) coordination polymers based on imidazole-containing ligands: synthesis, structural characterization and fluorescence properties.

The judicious selection of suitable ligands is vitally important in the construction of novel metal-organic frameworks (MOFs) with fascinating structures and interesting properties. Recently, imidazole-containing multidentate ligands have received much attention. Two new CdII coordination frameworks, namely, poly[tris{μ-1,4-bis[(1H-imidazol-1-yl)methyl]benzene-κ2N3:N3'}tetrakis(nitrato-κ2O,O')dicadmium], [Cd2(NO3)4(C14H14N4)3]n, (I), and poly[[bis{μ3-1,3,5-tris[(1H-imidazol-1-yl)methyl]benzene-κ3N3:N3':N3''}cadmium] hexafluorosilicate], {[Cd(C18H18N6)2](SiF6)}n, (II), have been synthesized and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. In polymer (I), the 1,4-bis[(1H-imidazol-1-yl)methyl]benzene ligand bridges Cd2+ ions with a distorted seven-coordinated pentagonal bipyramidal geometry, forming a one-dimensional ladder chain, and the nitrate anions coordinate to the Cd2+ ions in a terminal bidentate fashion. In the crystal, adjacent chains are further connected by C-H...O hydrogen bonds to generate a two-dimensional (2D) supramolecular structure. Polymer (II) exhibits a 2D layered structure in which 1,3,5-tris[(1H-imidazol-1-yl)methyl] benzene ligands join Cd2+ centres having a six-coordinated octahedral structure. The layers are connected by hexafluorosilicate anions via C-H...F hydrogen-bond interactions, giving rise to a three-dimensional supramolecular network structure in the solid state. In addition, powder X-ray diffraction (PXRD) patterns were recorded, thermogravimetric analyses (TGA) carried out and fluorescence properties investigated.

One- and Two-Dimensional Iodine-Rich Iodobismuthate(III) Complexes: Structure, Optical Properties, and Features of Halogen Bonding in the Solid State.

Reactions of BiI3, I2, and iodide salts of two different pyridinum cations result in the formation of the novel iodine-rich iodobismuthates(III) (1,3-MePy)4{[Bi4I16](I2)} (1) and (1-MePy){[BiI4](I2)0.5) (2), where the halometalate anions are connected by diiodine linkers into one- or two-dimensional supramolecular structures. Both complexes reveal narrow optical band gaps and fairly high thermal stability, favoring their potential use in photovoltaic devices.

Tetranuclear cobalt(II) and nickel(II) complexes with an unsymmetrical salamo-like ligand: Structural characterization, Hirshfeld analysis and fluorescent properties

Two newly designed tetranuclear transition metal(II) complexes, [{Co(L)(μ-OAc)Co(CH3OH)2}2] and [{Ni(L)(DMF)(μ-OAc)Ni}2] derived from an unsymmetrical salamo-like donor-N2O4 ligand (H3L: 6-hydroxy-6′-methoxy-2, 2′-[ethylenediyldioxybis(nitrilomethylidyne)]diphenol) were synthesized and characterized by elemental analysis, FT-IR, UV-vis, fluorescence spectroscopy, X-ray crystallography and Hirshfeld surface analysis. The Co(II) complex includes two fully deprotonated (L)3− moieties, two μ-acetato ligands and four coordinated methanol molecules, bearing a highly symmetrical tetranuclear structure. The terminal Co(II) ions are penta-coordinated and have slightly twisted triangular bipyramidal geometries, and the central Co(II) ions are hexa-coordinated and possess slightly twisted octahedral geometries. The Co(II) complex was self-assembled by adequate intermolecular hydrogen bonding interactions giving rise to an infinite two-dimensional supramolecular structure. The Ni(II) complex adopts a symmetric tetranuclear structure including two fully deprotonated (L)3− units, two coordinated DMF molecules, and two μ-acetato ligands. All the Ni(II) ions are hexa-coordinated and have slightly twisted octahedral geometries. At the same time, the fluorescent properties and Hirshfeld surfaces analyses of the Co(II) and Ni(II) complexes were also investigated in detail.

A cyanide-bridged FeIII-MnII heterobimetallic one-dimensional coordination polymer: synthesis, crystal structure, experimental and theoretical magnetism investigation.

A new cyanide-bridged FeIII-MnII heterobimetallic coordination polymer (CP), namely catena-poly[[[N,N'-(1,2-phenylene)bis(pyridine-2-carboxamidato)-κ4N,N',N'',N''']iron(III)]-μ-cyanido-κ2C:N-[bis(4,4'-bipyridine-κN)bis(methanol-κO)manganese(II)]-μ-cyanido-κ2N:C], {[FeMn(C18H12N4O2)(CN)2(C10H8N2)2(CH3OH)2]ClO4}n, (1), was prepared by the self-assembly of the trans-dicyanidoiron(III)-containing building block [Fe(bpb)(CN)2]- [bpb2- = N,N'-(1,2-phenylene)bis(pyridine-2-carboxamidate)], [Mn(ClO4)2]·6H2O and 4,4'-bipyridine, and was structurally characterized by elemental analysis, IR spectroscopy, single-crystal X-ray crystallography and powder X-ray diffraction (PXRD). Single-crystal X-ray diffraction analysis shows that CP 1 possesses a cationic linear chain structure consisting of alternating cyanide-bridged Fe-Mn units, with free perchlorate as the charge-balancing anion, which can be further extended into a two-dimensional supramolecular sheet structure via inter-chain π-π interactions between the 4,4'-bipyridine ligands. Within the chain, each MnII ion is six-coordinated by an N6 unit and is involved in a slightly distorted octahedral coordination geometry. Investigation of the magnetic properties of 1 reveals an antiferromagnetic coupling between the cyanide-bridged FeIII and MnII ions. A best fit of the magnetic susceptibility based on the one-dimensional alternating chain model leads to the magnetic coupling constants J1= -1.35 and J2 = -1.05 cm-1, and the antiferromagnetic coupling was further confirmed by spin Hamiltonian-based density functional theoretical (DFT) calculations.

Supramolecular first-row transition metal complexes of 3-(3,5-dimethylpyrazol-1-yl)propanamide: Three different coordination modes

Michael addition of 3-tert-butylpyrazole (1) or 3,5-dimethylpyrazole (2) to acrylamide afforded the pyrazolylpropanamide-type ligands 3-(3-tert-pyrazol-1-yl)propanamide (3, = tBuPPA) and 3-(3,5-dimethylpyrazol-1-yl)propanamide (4, = Me2PPA), respectively, in high isolated yields (3: 80%, 4: 76%). Reactions of 4 with selected first-row transition-metal chlorides (MnCl2·4H2O, CoCl2·6H2O, ZnCl2, CuCl2·2H2O) afforded the new complexes MnCl2(Me2PPA)2 (5), [MCl2(Me2PPA)]2 (M = Co (6), Zn (7)), and CuCl2(Me2PPA)2·2H2O (8). Ligand 3 and all four new complexes 5–8 have been structurally characterized though single-crystal X-ray diffraction. Surprisingly, the crystal structure determinations revealed three different coordination modes for the pyrazole-based ligand in these complexes. Seven-membered κN,κO-chelate rings are present in the manganese(II) complex 5. In contrast, κN: κO-bridging coordination of Me2PPA in compounds 6 and 7 leads to formation of dimers comprising 14-membered ring systems. Furthermore, unusual κN-monodentate coordination of Me2PPA has been found in the structure of the hydrated copper(II) complex Cu(Me2PPA)2Cl2·2H2O (8). In the crystalline state, all four complexes 5–8 form one- or two-dimensional supramolecular structures assembled through different types of hydrogen bonding.

The sodium chloride complex catena-poly[[{μ3-2-[bis(2-hydroxyethyl)amino]ethan-1-ol}sodium] chloride], N(CH2CH2OH)3·NaCl

The reaction of sodium chloride with 2-[bis(2-hydroxyethyl)amino]ethan-1-ol results in the formation of the title salt {[Na{N(CH2CH2OH)3}]Cl} n . The polymeric structure is characterized by a sodium cation coordinated by one nitrogen and five oxygen atoms in a distorted octahedral environment. The resulting one-dimensional {—O—Na—O—Na—O}— coordination polymer extends parallel to [010] and is connected through the chloride counter-anion via O—H...Cl hydrogen bonding, giving rise to a two-dimensional supramolecular structure parallel to (001).

Construction of two-dimensional supramolecular nanostructure with aggregation-induced emission effect via host–guest interactions

Formation of fluorescent two-dimensional supramolecular structure based on tetraphenylethene (TPE) derivative and CB[8].