catena‐Poly[[diaquabis(2‐chloronicotinato‐κ2O,O′)cadmium(II)]‐μ‐2‐chloronicotinato‐κ3O,O′:N]

In the title neutral coordination polymer, [Cd(C₆H₃ClNO₂)₂(H₂O)₂]_n, each Cd^II ion is coordinated by one N and four O atoms from three 2‐chloro­nicotinate ligands and by two aqua ligands, defining a distorted monocapped octahedral coordination geometry. Adjacent Cd atoms are linked by the pyridyl N atom and the bidentate carboxyl­ate functional group of a 2‐­chloro­nicotinate ligand, forming a one‐dimensional infinite chain along the b axis. The Cd⋯Cd distance is 8.112 (3) Å. These chains are linked by O—H⋯O and O—H⋯N hydrogen bonds into a three‐dimensional network structure.     

Bis­[bis­(pyrimidin‐2‐yl‐κN)­amine](dicyan­amido‐κN1)(tri­fluoro­methanesulfonato‐κO)copper(II) ethanol hemisolvate forms a hydrogen‐bonded chain

In the crystal structure of [Cu(CF₃SO₃)(C₂N₃)(C₈H₇N₅)₂]·0.5C₂H₆O, the Cu^II atom adopts a distorted octahedral geometry, with the basal plane formed by two N atoms of one dipyrimidinyl­amine ligand, one N atom of the second pyrimidine ligand and a nitrile N atom of the dicyan­amide anion [Cu—N = 1.972 (2)–2.021 (2) Å]. The apical positions are occupied by an N atom of the second ligand [Cu—N = 2.208 (2) Å], and an O atom of the tri­fluoro­methane­sulfonate anion [Cu—O = 2.747 (2) Å] at a semi‐coordination distance. Pairs of inversion‐related N—H⋯N hydrogen bonds of the so‐called Watson–Crick type, augmented by two C—H⋯N contacts, link adjacent complexes into an infinite one‐dimensional chain running in the [101] direction.     

Iodo­(picolinato‐κ2N,O)(picolinic acid‐κ2N,O)mercury(II)

The title compound, [Hg(C₆H₄NO₂)I(C₆H₅NO₂)], has twofold symmetry along the Hg—I bond. The Hg^II ion coordinates one I atom [at 2.6045 (4) Å], two N and two O atoms [at 2.298 (3) and 2.481 (2) Å] from one picolinate ion, and one picolinic acid mol­ecule in a very irregular trigonal–bipyramidal coordination. The single hydr­oxy H atom required for chemical neutrality is both statistically (by crystal symmetry) and structurally disordered, and is involved in an inter­molecular O—H⋯O hydrogen bond [O⋯O = 2.455 (4) Å], connecting the mol­ecules into one‐dimensional infinite chains along the [101] direction.     

mer‐Di­aqua­bis(1H‐imidazole‐κN3)(orotato‐κ2N3,O4)­nickel(II)

The title mononuclear complex, [Ni(C₅H₂N₂O₄)(C₃H₄N₂)₂(H₂O)₂] or [Ni(HOr)(im)₂(H₂O)₂] (im is imidazole and H₃Or is orotic acid, or 2,6‐dioxo‐1,2,3,6‐tetra­hydro­pyrimidine‐4‐carboxylic acid), has been synthesized and the crystal structure determination is reported. The Ni^II ion in the complex has a distorted octahedral coordination geometry comprised of one deprotonated pyrimidine N atom and the adjacent carboxyl­ate O atom of the orotate ligand, two tertiary imidazole N atoms and two aqua ligands. An extensive three‐dimensional network of OW—H⋯O and N—H⋯O hydrogen bonds, and π–π and π–ring interactions are responsible for crystal stabilization.     

trans‐Di­aqua­bis­(thio­semicarb­azido‐κ2N,S)­nickel(II) dimaleate dihydrate

In the title compound, [Ni(CH₅N₃S)₂(H₂O)₂](C₄H₃O₄)₂·2H₂O, the Ni atom lies on a center of symmetry and is coordinated by N and S atoms from two thio­semicarbazide ligands and the O atoms of two water mol­ecules in a distorted octahedral geometry. In the asymmetric unit, the three components are linked together by one O—H⋯O and two N—H⋯O hydrogen bonds. The packing is built from molecular ribbons parallel to the b direction, stabilized by intramolecular hydrogen bonds, and by one N—H⋯S and two N—H⋯O intermolecular hydrogen bonds. The ribbons are further connected into columns by N—H⋯O interactions and then into a three‐dimensional network by three O—H⋯O hydrogen bonds.     

catena‐Poly­[[(di‐2‐pyridyl­amine)­silver(I)]‐μ‐nicotinato] and catena‐poly­[[(di‐2‐pyridyl­amine)silver(I)]‐μ‐2,6‐di­hydroxy­benzoato]

In catena‐poly­[[(di‐2‐pyridyl­amine‐κ²N,N′)silver(I)]‐μ‐nico­tinato‐κ²N:O], [Ag(C₆H₄NO₂)(C₁₀H₉N₃)]_n, the Ag^I atom is tetracoordinated by two N atoms from the di‐2‐pyridyl­amine (BPA) ligand [Ag—N = 2.3785 (18) and 2.3298 (18) Å] and by one N atom and one carboxyl­ate O atom from nicotinate ligands [Ag—N = 2.2827 (15) Å and Ag—O = 2.3636 (14) Å]. Bridging by nicotinate N and O atoms generates a polymeric chain structure, which extends along [100]. The carboxyl O atom not bonded to the Ag atom takes part in an intrachain C—H⋯O hydrogen bond, further stabilizing the chain. Pairs of chains are linked by N—H⋯O hydrogen bonds to generate ribbons. There are no π–π interactions in this complex. In catena‐poly­[[(di‐2‐pyridyl­amine‐κ²N,N′)silver(I)]‐μ‐2,6‐di­hydroxy­benzoato‐κ²O¹:O²], [Ag(C₇H₅O₄)(C₁₀H₉N₃)]_n, the Ag^I atom has a distorted tetrahedral coordination, with three strong bonds to two pyridine N atoms from the BPA ligand [Ag—N = 2.286 (5) and 2.320 (5) Å] and to one carboxyl­ate O atom from the 2,6‐di­hydroxy­benzoate ligand [Ag—O = 2.222 (4) Å]; the fourth, weaker, Ag‐atom coordination is to one of the phenol O atoms [Ag⋯O = 2.703 (4) Å] of an adjacent moiety, and this interaction generates a polymeric chain along [100]. Pairs of chains are linked about inversion centers by N—H⋯O hydrogen bonds to form ribbons, within which there are π–π interactions. The ribbons are linked about inversion centers by pairs of C—H⋯O hydrogen bonds and additional π–π interactions between inversion‐related pairs of 2,6‐di­hydroxy­benzoate ligands to generate a three‐dimensional network.     

Three N2‐benzoyl­oxybenz­amidines: sheet structures built from hard and soft hydrogen bonds and aromatic π–π stacking interactions

Molecules of the title compounds N²‐(benzoyl­oxy)­benz­ami­dine, C₁₄H₁₂N₂O₂, (I), N²‐(2‐hydroxy­benzoyl­oxy)­benz­ami­dine, C₁₄H₁₂N₂O₃, (II), and N²‐benzoyloxy‐2‐hydroxybenzamidine, C₁₄H₁₂N₂O₃, (III), all have extended chain conformations, with the aryl groups remote from one another. In (I), the mol­ecules are linked into chains by a single N—H⋯N hydrogen bond [H⋯N = 2.15 Å, N⋯N = 3.029 (2) Å and N—H⋯N = 153°] and these chains are linked into sheets by means of aromatic π–π stacking interactions. There is one intramolecular O—H⋯O hydrogen bond in (II), and a combination of one three‐centre N—H⋯(N,O) hydrogen bond [H⋯N = 2.46 Å, H⋯O = 2.31 Å, N⋯N = 3.190 (2) Å, N⋯O = 3.146 (2) Å, N—H⋯N = 138° and N—H⋯O = 154°] and one two‐centre C—H⋯O hydrogen bond [H⋯O = 2.46 Å, C⋯O = 3.405 (2) Å and C—H⋯O = 173°] links the mol­ecules into sheets. In (III), an intramolecular O—H⋯N hydrogen bond and two N—H⋯O hydrogen bonds [H⋯O = 2.26 and 2.10 Å, N⋯O = 2.975 (2) and 2.954 (2) Å, and N—H⋯O = 138 and 163°] link the molecules into sheets.     

{μ‐N,N′‐Bis[3‐(dimethyl­amino)prop­yl]­oxamidato(2–)‐κ6N,N′,O′:N′′,N′′′,O}­bis­[(1H‐imidazole‐κN3)(methanol‐κO)copper(II)] bis­(perchlorate)

The structure of the title compound, [Cu₂(C₁₂H₂₄N₄O₂)(C₃H₄N₂)₂(CH₄O)₂](ClO₄)₂ or [Cu₂(dmoxpn)(HIm)₂(CH₃OH)₂](ClO₄)₂, where dmoxpn is the dianion of N,N′‐bis­[3‐(dimethyl­amino)prop­yl]oxamide and HIm is imidazole, consists of a centrosymmetric trans‐oxamidate‐bridged copper(II) binuclear cation, having an inversion centre at the mid‐point of the central C—C bond, and two perchlorate anions. The Cu^II atom has square‐pyramidal coordination geometry involving two N atoms and an O atom from the dmoxpn ligand, an N atom from an imidazole ring, and an O atom from a methanol mol­ecule. The crystal structure is stabilized by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds and imidazole π–π stacking inter­actions to form a three‐dimensional supra­molecular array.     

trans‐Di­aqua­bis(5‐carboxy‐1H‐imidazole‐4‐carboxyl­ato‐κ2N3,O4)­cobalt(II) 4,4′‐bi­pyridine solvate

In the title compound, [Co(C₅H₃N₂O₄)₂(H₂O)₂]·C₁₀H₈N₂, the Co atom is trans‐coordinated by two pairs of N and O atoms from two monoanionic 4,5‐di­carboxy­imidazole ligands, and by two O atoms from two coordinated water mol­ecules, in a distorted octahedral geometry. The 4,4′‐bi­pyridine solvent molecule is not involved in coordination but is linked by an N—H⋯N hydrogen bond to the neutral [Co(C₅H₃N₂O₄)₂(H₂O)₂] mol­ecule. Both mol­ecules are located on inversion centers. The crystal packing is stabilized by N—H⋯N and O—H⋯O hydrogen bonds, which produce a three‐dimensional hydrogen‐bonded network. Offset π–π stacking interactions between the pyridine rings of adjacent 4,4′‐bi­pyridine molecules were observed, with a face‐to‐face distance of 3.345 (1) Å.     

Tetra­aqua­(7‐hydroxy‐5‐oxidoflavone‐6‐sulfonato‐κ2O4,O5)nickel(II) dimethyl­formamide solvate monohydrate

In the title compound, [Ni(C₁₅H₈O₇S)(H₂O)₄]·C₃H₇NO·H₂O, the Ni^II cation is chelated by a 7‐hydroxy‐5‐oxidoflavone‐6‐sulfonate ligand through one oxide and one carbonyl O atom, and the sixfold coordination is completed by four aqua ligands. Individual mol­ecules are linked into hydrogen‐bonded dimers by way of five pairs of O—H⋯O hydrogen bonds. These dimers, in turn, determine a three‐dimensional supra­molecular arrangement through a variety of inter­dimeric inter­actions, such as O—H⋯O, C—H⋯O and π–π stacking.     

catena‐Poly[[[diaqua­bis(pyridine‐4‐carboxamide‐κN)copper(II)]‐μ2‐squarato‐κO1:O3] dihydrate]

The asymmetric unit of the title compound, {[Cu(C₄O₄)(C₆H₆N₂O)₂(H₂O)₂]·2H₂O}_n, consists of one pyridine‐4‐carbox­amide (isonicotinamide or ina) ligand, one‐half of a squarate dianion, a coordinated aqua ligand and a solvent water mol­ecule. Both the Cu^II and the squarate ions are located on inversion centers. The Cu^II ions are octa­hedrally surrounded by four O atoms of two water mol­ecules and two squarate anions, and by two N atoms of the isonicotinamide ligands. The crystal structure contains chains of squarate‐1,3‐bridged Cu^II ions. These chains are held together by N—H⋯O and O—H⋯O inter­molecular hydrogen‐bond inter­actions, forming an extensive three‐dimensional network.     

Hydro­gen‐bonded supramolecular motifs in 4,4′‐bipyridinium 8‐hydroxy‐7‐iodo­quinoline‐5‐sulfonate dihydrate

In the title compound, C₁₀H₉N₂⁺·C₉H₅INO₄S⁻·2H₂O, the 4,4′‐bi­pyridine mol­ecule is protonated at one of the pyridine N atoms. These moieties self‐assemble into a supramolecular chain along the a axis through N—H⋯N hydrogen bonds. The quinolinol OH group acts as a donor with respect to a sulfonate O atom [O—H⋯O(sulfonate)] and acts as an acceptor with respect to a C—H group of ferron [C—H⋯O(hydroxy)], forming a supramolecular chain along the b axis. These two types of supramolecular chains (one type made up of bi­pyridine motifs and the other made up of sulfoxine motifs) interact viaπ–π stacking, generating a three‐dimensional framework. These chains are further crosslinked by C—­H⋯O hydrogen bonds and O—H⋯O hydrogen bonds involving water mol­ecules.     

Bis(3‐amino­pyridine‐κN)(4,4′‐di­methyl‐2,2′‐bipyridine‐κ2N,N′)(per­chlorato‐κO)copper(II) per­chlorate

The title compound, [Cu(ClO₄)(C₅H₆N₂)₂(C₁₂H₁₂N₂)]ClO₄, was prepared by in situ partial ligand substitution between 3‐amino­pyridine and 4,4′‐dimethyl‐2,2′‐bipyridine at room temperature. The central copper(II) ion is five‐coordinated by one bidentate 4,4′‐dimethyl‐2,2′‐bipyridine mol­ecule, two monodentate pyridine‐coordinated 3‐amino­pyridine mol­ecules and one apical O atom from the perchlorate counter‐ion. Inter­molecular N—H⋯O and C—H⋯O hydrogen‐bonding inter­actions form a hydrogen‐bond‐sustained network.     

Bis(1,10‐phenanthroline‐κ2N,N′)(squarato‐κO)copper(II) trihydrate

The title mononuclear [Cu(sq)(phen)₂]·3H₂O complex [sq is squarate (C₄O₄) and phen is 1,10‐phenanthroline (C₁₂H₈N₂)] has been synthesized and the structure consists of a neutral mononuclear [Cu(sq)(phen)₂] unit and three solvate water mol­ecules. The Cu^II ion has distorted square‐pyramidal coordination geometry, comprised of one carboxyl­ate O atom from a monodentate squarate ligand and four N atoms from two chelating phen ligands. An extensive three‐dimensional network of OW—H⋯O/OW hydrogen bonds, face‐to‐face π–­π interactions between the 1,10‐phenanthroline aromatic rings and a weak π–ring interaction are responsible for crystal stabilization.     

Bis[1,1‐di­methyl­biguanide(1–)‐κ2N2,N5]copper(II) monohydrate

The crystal structure of the title compound, [Cu(C₄H₁₀N₅)₂]·H₂O, contains two independent copper N,N‐di­methyl­biguanide complex units, each with square‐planar coordination of the Cu atom by four N atoms. The two complexes have different symmetry, with one Cu atom lying on an inversion centre and the other on a twofold rotation axis. The Cu—N bond lengths are 1.923 (2) and 1.950 (2) Å in the centrosymmetric complex, and 1.928 (2) and 1.938 (2) Å in the non‐centrosymmetric complex. The crystal structure is stabilized by N—H⋯O, O—H⋯N and N—H⋯N hydrogen bonds; each water mol­ecule forms four hydrogen bonds involving three different Cu complexes.     

Bis(2,9‐dimethyl‐1,10‐phenanthroline‐κ2N,N′)copper(I) hydrogen squarate hemihydrate

In the crystal structure of the synthetically prepared title compound, [Cu(C₁₄H₁₂N₂)₂](C₄HO₄)·0.5H₂O or [Cu(dmphen)₂](HSq)·0.5H₂O (dmphen is 2,9‐dimethyl‐1,10‐phenanthroline or neocuproine and HSq is hydrogen squarate), the Cu^I centre has distorted tetra­hedral coordination geometry comprised of four N atoms from two bidentate dmphen ligands. The squarate monoanions form a ten‐membered dimer, graph set R₂²(10), linked by two strong inter­molecular O—H⋯O hydrogen bonds. These squarate dimers are linked into chains that propagate along the [100] direction. An extensive three‐dimensional network of C—H⋯O hydrogen bonds and π–π inter­actions is responsible for stabilization of the crystal structure.     

A bicapped trigonal–prismatic lead complex: catena‐poly[[[aqua­bis(1,10‐phenanthroline‐κ2N,N′)lead(II)]‐μ‐squarato‐κO1:κ2O2,O3] dihydrate]

The asymmetric unit of the title compound, {[Pb(C₄O₄)(C₁₂H₈N₂)₂(H₂O)]·2H₂O}_n, contains one squarate dianion, two phenanthroline (phen) ligands and one aqua ligand all coordinated to Pb, and two solvent water mol­ecules. The eight‐coordinate Pb metal ion displays a distorted bicapped trigonal–prismatic coordination environment, defined by three squarate O atoms, four N atoms from two chelating phen ligands and one O atom from the coordinated water mol­ecule. The crystal structure contains chains of squarate‐1,2,3‐bridged Pb^II ions running in the [010] direction. These polymeric chains are linked to one another via offset face‐to‐face π–π inter­actions between the phen ligands, which lead to a two‐dimensional network extending along the (001) plane. The crystal structure is also stabilized by O—H⋯O inter­molecular hydrogen‐bond inter­actions, forming a three‐dimensional network.     

Aqua(dipicolinato‐κ3O,N,O′)(1H‐imidazole‐κN3)(1,10‐phenanthroline‐N,N′)manganese(II)

In the title compound, [Mn(C₇H₃NO₄)(C₃H₄N₂)(C₁₂H₈N₂)(H₂O)], the Mn^II centre is surrounded by one bidentate phenanthroline ligand [Mn—N = 2.383 (3) and 2.421 (3) Å], one tridentate dipicolinate ligand [Mn—N = 2.300 (3) Å, and Mn—O = 2.300 (2) and 2.357 (2) Å], one monodentate imidazole ligand [Mn—N = 2.238 (3) Å] and one water molecule [Mn—O = 2.157 (3) Å]. It displays a distorted pentagonal‐bipyramidal geometry, with neighbouring angles within the equatorial plane ranging from 68.05 (9) to 77.48 (10)°. Intermolecular O—H...O hydrogen bonds link the molecules into infinite chains. The chains are crosslinked by hydrogen bonds involving the carboxyl O atoms of the dipicolinate ligand and the protonated imidazole N atom, leading to an infinite two‐dimensional network sheet packing mode. The complete solid‐state structure can be described as a three‐dimensional supramolecular framework, stabilized by these intermolecular hydrogen‐bonding interactions and π–π stacking interactions involving the phenanthroline rings.     

3,4‐Di‐2‐pyridyl‐1,2,5‐oxadiazole and its perchlorate salt

In 3,4‐di‐2‐pyridyl‐1,2,5‐oxadiazole (dpo), C₁₂H₈N₄O, each mol­ecule resides on a twofold axis and inter­acts with eight neighbours via four C—H⋯N and four C—H⋯O inter­actions to generate a three‐dimensional hydrogen‐bonded architecture. In the perchlorate analogue, 2‐[3‐(2‐pyrid­yl)‐1,2,5‐oxadiazol‐4‐yl]pyridinium perchlorate, C₁₂H₉N₄O⁺·ClO₄⁻ or [Hdpo]ClO₄, the [Hdpo]⁺ cation is bisected by a crystallographic mirror plane, and the additional H atom in the cation is shared by the two pyridyl N atoms to form a symmetrical intra­molecular N⋯H⋯N hydrogen bond. The cations and perchlorate anions are linked through C—H⋯O hydrogen bonds and π–π stacking inter­actions to form one‐dimensional tubes along the b‐axis direction.     

(2,2′‐Bipyridyl‐κ2N,N′)­bis­(salicyl­ato‐κ2O,O′)­zinc(II)

The asymmetric unit of the title compound, [Zn(C₇H₅O₃)₂(C₁₀H₈N₂)], contains one monomeric zinc complex. The Zn atom is coordinated to one 2,2′‐bipyridyl ligand via both N atoms and to two salicyl­ate anions (Hsal⁻) in a bidentate chelating manner involving carboxyl­ate O‐atom coordination. The complex exhibits a distorted octahedral geometry about the Zn^II atom, with the `apical' positions occupied by one of the two N atoms of the bipyridyl ligand and an O atom from one Hsal<sup>−</sup> ligand; the Zn atom is 0.168 (1) Å out of the `basal' plane. Two intramolecular six‐membered hydrogen‐bonded rings are present, generated from interactions between the carboxyl and hydroxyl groups of the salicyl­ate ligands. The crystal packing is governed by weak C—H⋯O and C—H⋯π interactions.