Three multinuclear Co(II), Zn(II) and Cd(II) complexes based on a single-armed salamo-type bisoxime: syntheses,structural characterizations and fluorescent properties

Three multinuclear complexes, [Co(L)(OAc)Co(CH₃CH₂OH)₂]·H₂O, [Zn(L)(OAc)Zn(CH₃OH)], and [{Cd(L)(OAc)Cd(CH₃OH)}₂], containing a single-armed salamo-type bisoxime H₃L have been synthesized and characterized structurally. The Co(II) complex forms a dimeric unit by intermolecular hydrogen bond interactions of neighboring dimeric molecules. The Zn(II) complex also forms a dimeric unit by intermolecular hydrogen bond interactions. Interesting features of the crystal structure include O?O short contacts. Meanwhile, self-assembling infinite 1-D, 2-D, and 3-D supramolecular structures are formed by intermolecular hydrogen bond and C–H?π interactions. The Cd(II) complex forms an infinite 2-D supramolecular structure by intermolecular hydrogen bond interactions. The photophysical properties of the Co(II), Zn(II), and Cd(II) complexes have also been discussed.     

A Schiff-base porphyrin complex with double intramolecular hydrogen bonds

We have designed a porphyrin with a Schiff-base substituent as a model to study intramolecular hydrogen-bonding. The corresponding complex [Zn(SATPP)(CH₃OH)] has been synthesized and characterized by X-ray crystallography, ¹H NMR, and UV-Vis spectroscopy. The structure shows that there are three phenyl groups and one salicylideneaminophenyl group at the meso positions of the porphyrin, and the phenol oxygen is involved in double hydrogen bonds, one within the salicylideneaminophenyl and the other between coordinated methanol and phenol oxygen. ¹H NMR spectra suggest that the binding of methanol to zinc is an equilibrium process in solution and the equilibrium constant has been determined by UV-Vis measurements. The intramolecular hydrogen bond stabilizes the structure, and the binding affinity increases 10 times over the corresponding TPP (TPP, dianion of meso-5,10,15,20-tetraphenylporphyrin).     

A DFT-based study of the hydrogen-bonding interactions between epicatechin and methanol/water

Tea polyphenols are essential components that give tea its medicinal properties. Methanol and water are frequently used as solvents in the extraction of polyphenols. Hydrogen-bonding interactions are significant in the extraction reaction. Density functional theory (DFT) techniques were used to conduct a theoretical investigation on the hydrogen-bonding interactions between methanol or water and epicatechin, an abundant polyphenol found in tea. After first analyzing the epicatechin monomer's molecular geometry and charge characteristics, nine stable epicatechin (EC) H₂O/CH₂OH complex geometries were discovered. The presence of hydrogen bonding in these improved structures has been proven. The calculated hydrogen bond structures are very stable, among which the hydrogen bond bonded with a hydroxyl group has higher stability. The nine complex structures’ hydrogen bonds were thought to represent closed-shell-type interactions. The interaction energy with 30O-31H on the epicatechin benzene ring is the strongest in the hydrogen bond structure. While the other hydrogen bonds were weak in strength and mostly had an electrostatic nature, the hydrogen bonds between the oxygen atoms in H₂O or CH₂OH and the hydrogen atoms of the hydroxyl groups in epicatechin were of moderate strength and had a covalent character. Comparing the changes in the hydrogen bond structure vibration peak, the main change in concentration peak is the hydrogen bond vibration peak in the complex. Improved the study on the hydrogen bond properties of CH₂OH and H₂O of EC.     

Syntheses,structures, and luminescence of coordination compounds based on N-containing polycarboxylates

Six coordination compounds constructed by two structurally related flexible nitrogen-containing polycarboxylate ligands 2,2′-(2,2′-(ethane-1,2-diylbis(oxy))bis(2,1-phenylene))bis(methylene)bis(azanediyl)dibenzoic acid (H₂L1) and 5,5′-(2,2′-(ethane-1,2-diylbis(oxy))bis(2,1-phenylene))bis(methylene)bis(azanediyl)diisophthalic acid (H₄L2) have been synthesized: [Ni(H₂O)₆]?·?L1?·?(C₂H₅OH)_0.5?·?H₂O (1), [Co(L1)(L3)]?·?CH₃OH (2), [Ni(L1)(L3)]?·?CH₃OH (3), [Zn(L1)(L3)]?·?CH₃OH (4), [Cd(L1)(L3)]?·?CH₃OH (5), and [Zn(L2)_0.5(phen)]?·?C₂H₅OH (6), where L3?=?3,4?:?9,10?:?17,18?:?23,24-tetrabenzo-1,12,15,26-tetraaza-5,8,19,22-tetraoxacyclooctacosan and phen?=?1,10-phenanthroline. The crystal structures have been determined by single-crystal X-ray diffraction. Compound 1 displays a discrete structure, which is further linked by hydrogen bonds to form a 2-D supramolecular layer. Compounds 2–5 display similar structures. These compounds possess 1-D meso-chain structures linked by L1 and metals. The C–H?···?π interactions from neighboring chains extend the chains in different directions, giving a 3-D plywood network. Compound 6 possesses 2-D layers, which are further linked by hydrogen-bonding interactions to generate a 3-D supramolecular architecture.     

Synthesis,crystal structures,and properties of copper(II) complexes with 2,6-bis(benzimidazol-2-yl)pyridine

Three new mononuclear copper(II) complexes, [CuL(2-fca)(CH₃OH)]ClO₄?·?CH₃OH (1), [CuL(m-nba)(CH₃OH)]ClO₄ (2), and [CuL(pic)(ClO₄)]?·?CH₃OH (3), were synthesized and structurally characterized, where L is 2,6-bis(benzimidazol-2-yl)pyridine, while 2-fca, m-nba, and pic are the anions of 2-furoic acid, m-nitrobenzoic acid, and picolinic acid, respectively. All of them were characterized by elemental analysis, infrared, UV-Vis, and X-ray crystallography. In 1 and 2, the Cu(II) resides within a distorted square-pyramidal N₃O₂ coordination sphere with three nitrogens of L, one carboxylate oxygen, and one methanol. In 3, Cu(II) is coordinated with three nitrogens of L, one nitrogen and one oxygen of picolinate, and one oxygen of perchlorate in a distorted octahedral geometry. Two molecules of 1, 2, and 3 are interacted by intermolecular hydrogen-bonding interactions and strong π–π stacking interactions to form a dinuclear structural unit. The dinuclear units are further connected by H-bonds via perchlorate or lattice methanol to form a 1-D chain for 1 and 2-D network structures for 2 and 3. Hydrogen-bonding and π–π stacking interactions are important for the stabilization of the final supramolecular structures of the three complexes.     

Metal complexes of a phenol-tailed porphyrin with different hydrogen bonds

Hydrogen bonds are very common and important interactions in biological systems, they are used to control the microenvironment around metal centers. It is a challenge to develop appropriate models for studying hydrogen bonds. We have synthesized two metal complexes of the phenol-tailed porphyrin, [Zn(HL)] and [Fe(HL)(C₆H₄(OH)(O))]. X-ray crystallography reveals that the porphyrin functions as a dianion HL^2? and the phenol OH is involved in hydrogen bonds in both structures. In [Zn(HL)], an intramolecular hydrogen bond is formed between the carbonyl oxygen and OH. In [Fe(HL)(C₆H₄(OH)(O))], the unligated O(5) of the ligand is involved in two hydrogen bonds, as a hydrogen bond donor and a hydrogen bond acceptor. The overall electronic effect on the ligand could be very small, with negligible impact on the structure and the spin state of iron(III). The structural differences caused by the hydrogen bonds are also discussed.     

Syntheses,structures, and luminescence of three 4-connected zinc coordination polymers with bis(1,2,4-triazol-1-yl)propane and benzenebiscarboxylate

Three zinc(II) coordination polymers {[Zn(btp)(1,2-bdc)(H₂O)]?·?H₂O} _n (1), {[Zn(btp)(1,3-bdc)(H₂O)]?·?1.5H₂O} _n (2), and {[Zn(btp)(NO₂-1,3-bdc)(H₂O)]?·?2H₂O} _n (3) were synthesized by 1,3-bis(1,2,4-triazol-1-yl)propane (btp) and bis-carboxylate. Compound 1 is a thick 2-D network; 2 and 3 are undulated 2-D (4,4) networks. In 2 and 3, two adjacent networks interpenetrate to form a new 2-D double-layer network, which is sustained by hydrogen-bonding interactions. Compounds 1 and 2 reveal blue emission maximum at 351 and 403, respectively, in the solid state at room temperature.     

Copper(II) and lanthanoid(III) complexes of a new β-diketonate ligand with an appended non-coordinating phenol group

New mononuclear compounds of the ligand 1-(2-hydroxyphenyl)-3-phenylpropane-1,3-dione (H₂L) with Cu(II) and several lanthanoid(III) ions, where Ln(III) = Pr, Nd, Eu, Gd, have been synthesized and characterized by spectroscopic methods and X-ray crystal structure determinations. In all compounds, the ligand coordinates in a bidentate chelating manner, using the diketone function. In the [Cu(HL)₂], the coordination geometry of Cu(II) ion is slightly distorted square-planar; two strong intramolecular (OH?O) hydrogen-bonding interactions are established between the phenolate group and the neighboring ketone function. The lanthanoid(III) compounds have the general formula [Ln(HL)₃(CH₃OH)₂] · CH₃OH · 2H₂O; the lanthanoid(III) ion (Ln) is eight-coordinated and the coordination geometry is based on a distorted square-antiprism. In addition to the intramolecular hydrogen bonding (OH?O), intermolecular hydrogen-bonding interactions are also present between the coordinated methanol molecule and the non-coordinated methanol molecule giving rise to a three-dimensional network.     

Diacetatobis­(tri­methyl­ene­thio­urea)­zinc(II) monohydrate

In the title compound, [Zn(CH₃COO)₂(C₄H₈N₂S)₂]·H₂O, the Zn atom is tetrahedrally coordinated in the ZnO₂S₂ form. N—H?O and O—H?O intramolecular and intermolecular hydrogen bonds are formed by the four N atoms and the water mol­ecule. N—H?O intermolecular hydrogen bonds and C—H?S and C—H?O intermolecular interactions interconnect columns formed by the mol­ecules into layers. Adjacent layers are then linked by other N—H?O and O—H?O intermolecular hydrogen bonds to form a three‐dimensional framework throughout the structure. The orientations of the acetate planes are such that the Zn atom lies within them.     

New mixed-anion zinc(II) complexes, [Zn(phen)2(CCl3COO)(H2O)](NO3) and [Zn(bpy)2(CH3COO)](ClO4) · H2O; synthesis,characterization and crystal structures

Zinc(II) complexes with 1,10-phenanthroline (phen) and 2,2′-bipyridine (bpy) containing two different anions have been synthesized and characterized by elemental analysis, IR-, ¹H?NMR-, ¹³C?NMR spectroscopy. The single crystal X-ray data of [Zn(phen)₂(CCl₃COO)(H₂O)](NO₃) show the complex to be monomeric and the Zn atom with an unsymmetrical six-coordinate geometry, coordinated by four nitrogen atoms of “phen”, one trichloroacetate and one water. The crystal structure of [Zn(bpy)₂(CH₃COO)](ClO₄)?·?H₂O shows each zinc atom chelated by the nitrogen atoms of “bpy” and also two oxygen atoms of acetate. From the infrared spectra and X-ray crystallography, it is established that coordination of the carboxylate group to zinc is different for trichloroacetate and acetate.     

Isomorphous rare‐earth tris[bis(2,6‐diisopropylphenyl) phosphate] complexes and their catalytic properties in 1,3‐diene polymerization and in the inhibited oxidation of polydimethylsiloxane

Crystals of mononuclear tris[bis(2,6‐diisopropylphenyl) phosphato‐κO]pentakis(methanol‐κO)lanthanide methanol monosolvates of lanthanum, [La(C₂₄H₃₄O₄P)₃(CH₃OH)₅]·CH₃OH, ( 1 ), cerium, [Ce(C₂₄H₃₄O₄P)₃(CH₃OH)₅]·CH₃OH, ( 2 ), and neodymium, [Nd(C₂₄H₃₄O₄P)₃(CH₃OH)₅]·CH₃OH, ( 3 ), have been obtained by reactions between LnCl₃(H₂O)_n (n = 6 or 7) and lithium bis(2,6‐diisopropylphenyl) phosphate in a 1:3 molar ratio in methanol media. Compounds ( 1 )–( 3 ) crystallize in the monoclinic P2₁/c space group and have isomorphous crystal structures. All three bis(2,6‐diisopropylphenyl) phosphate ligands display a κO‐monodentate coordination mode. The coordination number of the metal atom is 8. Each [Ln{O₂P(O‐2,6‐ⁱPr₂C₆H₃)₂}₃(CH₃OH)₅] molecular unit exhibits four intramolecular O—H…O hydrogen bonds, forming six‐membered rings. The unit forms two intermolecular O—H…O hydrogen bonds with one noncoordinating methanol molecule. All six hydroxy H atoms are involved in hydrogen bonding within the [Ln{O₂P(O‐2,6‐ⁱPr₂C₆H₃)₂}₃(CH₃OH)₅]·CH₃OH unit. This, along with the high steric hindrance induced by the three bulky diaryl phosphate ligands, prevents the formation of a hydrogen‐bond network. Complexes ( 1 )–( 3 ) exhibit disorder of two of the isopropyl groups of the phosphate ligands. The cerium compound ( 2 ) demonstrates an essential catalytic inhibition in the thermal decomposition of polydimethylsiloxane in air at 573 K. Catalytic systems based on the neodymium complex tris[bis(2,6‐diisopropylphenyl) phosphato‐κO]neodymium, ( 3′ ), which was obtained as a dry powder of ( 3 ) upon removal of methanol, display a high catalytic activity in isoprene and butadiene polymerization.     

Hydrogen bonding in triamine copper(II) P,P′-Diphenylmethylenediphosphinate (pcp2−) hybrids. Syntheses and crystal structures of [Cu(pcp) (2,2′-dipyridylamine)(H2O)] · 2H2O and [Cu(pcp)(2,2′ : 6′,2′′terpyridine)] · 4H2O

Two hybrid materials [Cu(pcp)(dipyam)(H₂O)]?·?2H₂O (1) and [Cu(pcp)(terpy)]?·?4H₂O (2), have been prepared by reaction of copper(II) acetate monohydrate with P,P′ diphenylmethylenephosphinic acid (H₂pcp) and 2,2′ dipyridylamine (dipyam) or 2,2′?:?6′,2′′ terpyridine (terpy), and have been structurally characterized by X-ray analyses. Both structures have a three-dimensional architecture, created by a close network of hydrogen bonding interactions. The copper centers present approximate square-pyramidal coordination, surrounded by pcp, dipyam and one water molecule in 1, and by pcp and terpyridine in 2. In both complexes the pcp ligand chelates only one metal, so that the free phenylphosphinate oxygens remain available for hydrogen-bonding interactions with water molecules, present in coordinated and solvated forms in 1 and solely as the solvated form in 2.     

Isomorphous rare‐earth bis[bis(2,6‐diisopropylphenyl)phosphate] complexes and their self‐assembly into two‐dimensional frameworks by intramolecular hydrogen bonds

The crystal structures of rare‐earth diaryl‐ or dialkylphosphate derivatives are poorly explored. Crystals of bis[bis(2,6‐diisopropylphenyl)phosphato‐κO ]chloridotetrakis(methanol‐κO )neodymium methanol disolvate, [Nd(C₂₄H₃₄O₄P)Cl(CH₄O)₄]·2CH₃OH, (1), and of the lutetium, [Lu(C₂₄H₃₄O₄P)Cl(CH₄O)₄]·2CH₃OH, (2), and yttrium, [Y(C₂₄H₃₄O₄P)Cl(CH₄O)₄]·2CH₃OH, (3), analogues have been obtained by reactions between lithium bis(2,6‐diisopropylphenyl)phosphate and LnCl₃(H₂O)₆ (in a 2:1 ratio) in methanol. Compounds (1)–(3) crystallize in the C 2/c space group. Their crystal structures are isomorphous. The molecule possesses C ₂ symmetry with a twofold crystallographic axis passing through the Ln and Cl atoms. The bis(2,6‐diisopropylphenyl)phosphate ligands all display a κ¹O‐monodentate coordination mode. The coordination polyhedron for the metal atom [coordination number (CN) = 7] is a distorted pentagonal bipyramid. Each [Ln{O₂P(O‐2,6‐ⁱPr₂C₆H₃)₂}₂Cl(CH₃OH)₄] molecular unit exhibits two intramolecular O—H…O hydrogen bonds, forming six‐membered rings, and two intramolecular O—H…Cl interactions, forming four‐membered rings. Intermolecular O—H…O hydrogen bonds connect each unit via four noncoordinating methanol molecules with four other units, forming a two‐dimensional hydrogen‐bond network. Crystals of bis[bis(2,6‐diisopropylphenyl)phosphato‐κO ]tetrakis(methanol‐κO )(nitrato‐κ²O ,O ′)neodymium methanol disolvate, [Nd(C₂₄H₃₄O₄P)(NO₃)(CH₄O)₄]·2CH₃OH, (4), have been obtained in an analogous manner from NdCl₃(H₂O)₆. Compound (4) also crystalizes in the C 2/c space group. Its crystal structure is similar to those of (1)–(3). The κ²O ,O ′‐bidentate nitrate anion is disordered over a twofold axis, being located nearly on it. Half of the molecule is crystallographically unique (CN_Nd = 8). Unlike (1)–(3), complex (4) exhibits disorder of all three methanol molecules, one isopropyl group of the phosphate ligand and the NO₃⁻ ligand. The structure of (4) displays intra‐ and intermolecular O—H…O hydrogen bonds similar to those in (1)–(3). Compounds (1)–(4) represent the first reported mononuclear bis[bis(diaryl/dialkyl)phosphate] rare‐earth complexes.     

含二茂铁基的锌配合物的结构及其生物活性

合成了4个含二茂铁基的锌配合物[Zn(FcCOO)(phen)₂]ClO₄·FcCOOH (1)(FcCOO=二茂铁甲酸根,phen=1,10-邻菲咯啉),[Zn(FcCOO)(phen)₂]·ClO₄·H₂O (2),[Zn(FcCOO)(FcCOGly)(phen)]·C₂H₅OH (3)(FcCOGly=二茂铁甲酰化甘氨酸)和[Zn(FcCOGly)₂(phen)]·CH₃OH (4)。用X-射线单晶衍射测定了配合物的晶体结构。对4个配合物的生物活性进行了初步研究,发现配合物的抗菌活性与配合物的配位键强度及phen含量有一定的关系。     

Mononuclear nickel(II) and zinc(II) complexes with deprotonated forms of the tripodal hexadentate ligand 1,3‐bis(2‐hydroxybenzylidene)‐2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methylpropane‐1,3‐diamine

In the crystal structures of both title compounds, [1,3‐bis(2‐hydroxybenzylidene)‐2‐methyl‐2‐(2‐oxidobenzylideneaminomethyl)propane‐1,3‐diamine]nickel(II) [2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methyl‐1,3‐bis(2‐oxidobenzylidene)propane‐1,3‐diamine]nickel(II) chloride methanol disolvate, [Ni(C₂₆H_25.5N₃O₃)]₂Cl·2CH₄O, and [1,3‐bis(2‐hydroxybenzylidene)‐2‐methyl‐2‐(2‐oxidobenzylideneaminomethyl)propane‐1,3‐diamine]zinc(II) perchlorate [2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methyl‐1,3‐bis(2‐oxidobenzylidene)propane‐1,3‐diamine]zinc(II) methanol trisolvate, [Zn(C₂₆H₂₅N₃O₃)]ClO₄·[Zn(C₂₆H₂₆N₃O₃)]·3CH₄O, the 3d metal ion is in an approximately octahedral environment composed of three facially coordinated imine N atoms and three phenol O atoms. The two mononuclear units are linked by three phenol–phenolate O—H...O hydrogen bonds to form a dimeric structure. In the Ni compound, the asymmetric unit consists of one mononuclear unit, one‐half of a chloride anion and a methanol solvent molecule. In the O—H...O hydrogen bonds, two H atoms are located near the centre of O...O and one H atom is disordered over two positions. The Ni^II compound is thus formulated as [Ni(H_1.5L)]₂Cl·2CH₃OH [H₃L is 1,3‐bis(2‐hydroxybenzylidene)‐2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methylpropane‐1,3‐diamine]. In the analogous Zn^II compound, the asymmetric unit consists of two crystallographically independent mononuclear units, one perchlorate anion and three methanol solvent molecules. The mode of hydrogen bonding connecting the two mononuclear units is slightly different, and the formula can be written as [Zn(H₂L)]ClO₄·[Zn(HL)]·3CH₃OH. In both compounds, each mononuclear unit is chiral with either a Δ or a Λ configuration because of the screw coordination arrangement of the achiral tripodal ligand around the 3d metal ion. In the dimeric structure, molecules with Δ–Δ and Λ–Λ pairs co‐exist in the crystal structure to form a racemic crystal. A notable difference is observed between the M—O(phenol) and M—O(phenolate) bond lengths, the former being longer than the latter. In addition, as the ionic radius of the metal ion decreases, the M—O and M—N bond distances decrease.     

Synthesis,spectroscopic, and structural characterization of two malate zinc coordination polymers with imidazole or 2,2′-bipyridine

Zinc(II) coordination polymers, [Zn(Hmal)(im)(H₂O)] _n · 2nH₂O (1) and [Zn(Hmal)(bpy)] _n · 3nH₂O (2) (H₃mal = malic acid, im = imidazole, bpy = 2,2′-bipyridine), were synthesized from aqueous solution and characterized by elemental analyses, infrared and fluorescence spectra, thermogravimetric analyses, and single-crystal X-ray structural analyses. In 1, zinc is coordinated by imidazole, water, and tridentate malate in octahedral geometry. The β-carboxy group of malate further bridges with the other zinc forming 1-D polymeric chains. A pair of 1-D chains self-assemble to generate a double chain by strong hydrogen bonds between imidazole and malate. Furthermore, neighboring pairs of double chains are extended to form the final 3-D framework through intermolecular hydrogen bonds. In 2, the malates link Zn in a bidentate–monodentate fashion to form spiral-shaped chains that extend into a 3-D supramolecular structure by π–π stacking interactions and intermolecular hydrogen bonds. Complex 1 exhibits strong fluorescence at room temperature.     

Self-assembly of two zinc(II) supramolecular architectures with carboxylate and chelating aromatic amine ligands: [Zn(nba)2(phen)(H2O)] and [Zn(nip)(phen)]n (nba = 4-nitrobenzoic acid, nip = 5-nitroisophthalic acid)

Two new zinc(II) compounds, [Zn(nba)₂(phen)(H₂O)] (1) and [Zn(nip)(phen)] _n (2) [nba = 4-nitrobenzoic acid, nip = 5-nitroisophthalic acid, phen = 1,10-phenanthroline] have been hydrothermally synthesized by reaction of zinc acetate and phen with the ligands nba and nip, respectively. Compound (1) consists of mononuclear zinc(II) molecules which forms a 2D supramolecular structure based on hydrogen bonds between the hydroxyl groups (and aromatic groups as well) and carboxylate oxygen atoms. Compound (2) displays 1D zigzag chains which are combined to 1D supramolecular double-chains by π–π stacking and further assembled into a 3D supramolecular framework through hydrogen bonds.     

Synthesis,crystal structure,and density functional theory study of a zinc(II) complex containing terpyridine and pyridine-2,6-dicarboxylic acid ligands: Analysis of the interactions with amoxicillin

An octahedral zinc(II) complex of 2,2′:6′,2″-terpyridine (Tpy) and pyridine-2,6-dicarboxylate (Pydc), [Zn(II)(Tpy)(Pydc)·4H₂O] was synthesized and its structure was determined by a single-crystal X-ray diffraction. The ligand pyridine-2,6-dicarboxylate coordinated to the zinc(II) ion via two pairs of carboxylate oxygens and one nitrogen atom, whereas 2,2′:6′,2″-terpyridine also contributed three coordination bonds through its nitrogen atoms. [Zn(II)(Tpy)(Pydc)·4H₂O] showed luminescence properties between 412 and 435 nm in DMSO. The solid-state octahedral geometry of [Zn(II)(Tpy)(Pydc)·4H₂O] was also preserved in solution as confirmed by the observed UV λ_ex = 346. Experimental and theoretical studies indicated that [Zn(II)(Tpy)(Pydc)·4H₂O] interacted with amoxicillin. Density functional theory calculations at B3LYP/LanL2dz level of theory suggested that [Zn(II)(Tpy)(pydc)·4H₂O] dimer interacts with (2S,5R,6R)-6-{[(2R)-2-amino-2-(4-hydroxyphenyl)-acetyl]amino}-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-24-carboxylic acid (amoxicillin) via highest occupied molecular orbital and lowest unoccupied molecular orbital, π–π interaction, hydrogen bond interaction, and van der Waals forces, thus influencing [Zn(II)(Tpy)(Pydc)·4H₂O] properties.     

A new coordination mode of 6‐methylnicotinic acid in trans‐tetraaquabis(6‐methylpyridine‐3‐carboxylato‐κO)cobalt(II) tetrahydrate

The title compound, [Co(C₇H₆NO₂)₂(H₂O)₄]·4H₂O, contains a Co^II ion lying on a crystallographic inversion centre. The Co^II ion is octahedrally coordinated by two 6‐methylpyridine‐3‐carboxylate ligands in axial positions [Co—O = 2.0621 (9) Å] and by four water molecules in the equatorial plane [Co—O = 2.1169 (9) and 2.1223 (11) Å]. There are also four uncoordinated water molecules. The 6‐methylpyridine‐3‐carboxylate ligands are bound to the Co^II ion in a monodentate manner through a carboxylate O atom. There is one strong intramolecular O—H...O hydrogen bond, and six strong intermolecular hydrogen bonds of type O—H...O and one of type O—H...N in the packing, resulting in a complex three‐dimensional supramolecular structure.     

(R)‐(6,6′‐Dihydroxybiphenyl‐2,2′‐diyl)bis(diphenylphosphine oxide) methanol solvate

The title compound, C₃₆H₂₈O₄P₂·CH₄O, was synthesized directly from the methoxy analogue. The crystal structure shows that one OH group interacts with an O atom of a phosphine oxide group in an adjacent mol­ecule, while the other OH group complexes with the methanol solvent molecule via intermolecular hydrogen bonds. An O atom of one phosphine oxide group interacts with the hydroxy H atom of methanol via a hydrogen bond. There are intra‐ and intermolecular π–π interactions between the phenyl rings. All these interactions result in the formation of supramolecular chiral parallelogram channels via self‐assembly.