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.     

Poly­[iron(II)‐di‐μ‐imidazole‐4,5‐di­carboxyl­ato‐κ3N3,O4:O5]

In the title compound, [Fe(C₅H₃N₂O₄)₂]_n, each Fe atom lies on a centre of symmetry, in an octahedral coordination environment consisting of two chelate rings [Fe—N = 2.154 (3) Å and Fe—O = 2.180 (3) Å] and two carboxyl­ate O atoms [Fe—O = 2.111 (2) Å] from imidazole‐4,5‐di­carboxyl­ate ligands. Extensive hydrogen‐bonding interactions exist between layers constructed of Fe₄ squares, forming tunnels along the a axis with large voids.     

trans‐Di­aqua­bis(6‐hydroxy­picolinato‐κ2N,O2)copper(II)

In the title compound, [Cu(C₆H₄NO₃)₂(H₂O)₂], the Cu^II ion lies on an inversion centre and has an elongated octahedral environment, equatorially trans‐coordinated by two N,O‐bidentate picolinate ligands and axially coordinated by two water O atoms. The complex mol­ecules form layers, which are linked by O—H⋯O hydrogen bonds between the aqua ligands and neighbouring carboxyl­ate groups. An intramolecular hydrogen bond between the coordinated carboxyl­ate O atom and the hydroxy H atom is also observed.     

5‐n‐Butylpyridine‐2‐carboxylate–copper(II) and –iron(III) complexes

In trans‐bis(5‐n‐butyl­pyridine‐2‐carboxyl­ato‐κ²N,O)­bis­(methanol‐κO)copper(II), [Cu(C₁₀H₁₂NO₂)₂(CH₄O)₂], the Cu atom lies on a centre of symmetry and has a distorted octahedral coordination. The Cu—O(methanol) bond length in the axial direction is 2.596 (3) Å, which is much longer than the Cu—­O(carboxylate) and Cu—N distances in the equatorial plane [1.952 (2) and 1.977 (2) Å, respectively]. In mer‐tris(5‐n‐bu­tyl­pyridine‐2‐carboxyl­ato‐κ²N,O)­iron(III), [Fe(C₁₀H₁₂NO₂)₃], the Fe atom also has a distorted octahedral geometry, with Fe—O and Fe—N bond‐length ranges of 1.949 (4)–1.970 (4) and 2.116 (5)–2.161 (5) Å, respectively. Both crystals are stabilized by stacking interactions of the 5‐n‐butyl­pyridine‐2‐carboxyl­ate ligand, although hydrogen bonds also contribute to the stabilization of the copper(II) complex.     

catena‐Poly[[copper(II)‐μ‐2‐[bis­(2‐pyridylmeth­yl)amino]butyrato‐κ4N,N′,N′′,O:κO′] perchlorate]

The copper(II) ion in the syn–anti carboxyl­ate‐bridged one‐dimensional zigzag chain title complex, {[Cu(C₁₆H₁₈N₃O₂)]ClO₄}_n, exhibits a distorted trigonal–bipyramidal environment. Two N atoms and one carboxyl­ate O atom of the ligand form the basal plane, while the axial positions are filled by an N atom of the ligand and one O atom belonging to the carboxyl­ate group of an adjacent mol­ecule. The crystal packing is enhanced by C—H⋯O(perchlorate) hydrogen bonds.     

Bis{μ‐2‐[(2,3‐dichloro­phenyl)­amino]­benzoato‐κO}di‐μ2‐ethoxo‐octa­methyl­di‐μ3‐oxo‐tetra­tin(IV)

The title compound, [Sn₄(CH₃)₈(C₁₃H₈Cl₂NO₂)₂(C₂H₅O)₂O₂], is a centrosymmetric dimer, with three linearly fused four‐membered Sn—O—Sn—O rings. The coordination poly­hedron of the Sn atom bonded to the carboxyl­ate can be described as trigonal–bipyramidal distorted toward square‐pyramidal. That of the second Sn atom is similar, but the distortion towards square‐pyramidal geometry is greater. The Sn—O and Sn—C distances are 2.020 (2)–2.226 (2) and 2.096 (4)–2.114 (4) Å, respectively. The benzene rings of the 2‐[(2,3‐dichloro­phenyl)­amino]benzoate ligand subtend an angle of 50.49 (17)°; the conformation of the ligand is stabilized by intra­molecular N—H⋯Cl and N—H⋯O hydrogen bonds. The structure is assembled viaπ–π stacking inter­actions to form chains parallel to [10].     

catena‐Poly­[[tri‐n‐butyl­tin]‐μ‐N‐(1‐naphthyl)­maleamato]

The crystal structure of catena‐poly­[[tri‐n‐butyl­tin]‐μ‐3‐(1‐naph­thyl­amino­carbonyl)­acrylato‐κ²O¹:O³], [Sn(C₄H₉)₃(C₁₄H₁₀NO₃)]_n, is composed of polymeric chains wherein the metal center exhibits a distorted trigonal‐bipyramidal geometry, with three n‐butyl groups defining the trigonal plane [mean Sn—C 2.133 (7) Å] and the axial positions being occupied by the carboxyl­ate O atoms of two different N‐(1‐naphthyl)­maleamate ligands with inequivalent Sn—O distances [2.167 (4) and 2.457 (4) Å]. The N‐(1‐naphthyl)­maleamate fragment forms an essentially planar seven‐membered ring involving an intramolecular N—H?O hydrogen bond.     

catena‐Poly[[[triaqua­cobalt(II)]‐μ‐2,6‐dioxo‐1,2,3,6‐tetra­hydro­pyrimidine‐4‐carboxyl­ato(2–)] 1.72‐hydrate]

The Co^II ion in the title complex {[Co(C₅H₂N₂O₄)(H₂O)₃]·1.72H₂O}_n, has a distorted octa­hedral coordination geometry comprised of three water ligands, one deprotonated pyrimidine N atom and an adjacent carboxyl­ate O atom of one orotate ligand. The sixth coordination site is occupied by an exocyclic O atom from a neighbouring orotate moiety, and through this inter­action a helicoidal chain is formed. The mol­ecules are linked by intra­molecular O_water—H⋯O and inter­molecular N—H⋯O and O_water—H⋯O hydrogen bonds, forming a three‐dimensional network.     

Polymeric μ‐bromo‐μ‐pyridine‐3‐carboxyl­ato‐κ3O,O′:N‐mercury(II)

The asymmetric unit of the title polymeric complex, [HgBr(C₆H₄NO₂)]_n or HgBr(nic), contains mercury coordinated via two Br atoms [Hg—Br = 2.6528 (9) and 2.6468 (9) Å], two carboxyl­ate O atoms, which form a characteristic four‐membered chelate ring [Hg—O = 2.353 (6) and 2.478 (7) Å], and an N atom [Hg—N = 2.265 (5) Å], in the form of a very irregular (3+2)‐coordination polyhedron. The pronounced irregularity of the effective Hg (3+2)‐coordination is a result of the rigid stereochemistry of the nicotinate ligand. According to the covalent and van der Waals radii criteria, the strongest bonds are Hg—Br and Hg—N. These covalent interactions form a two‐dimensional poly­mer. The puckered planes are connected by van der Waals interactions, and there are only two intermolecular C—H⋯O hydrogen bonds [3.428 (10) and 3.170 (10) Å].     

Orthorhombic modification of tri­phenyl­tin 3‐ureidopropionate

The Sn atom in catena‐poly­[tri­phenyl­tin(IV)‐μ‐(3‐ureidopropionato‐O¹:O³)], [Sn(C₆H₅)₃(C₄H₇N₂O₃)]_n, is five‐coordinate and has a trans‐C₃SnO₂ trigonal‐bipyrmidal geometry arising from bridging through the O atom of the ureido fragment of an adjacent carboxyl­ate group. Infinite chains propagate helically along the c axis and adjacent chains are linked by N—H?O [N?O 2.851 (4) Å] hydrogen bonds into layers.     

Tetrakis(μ‐guanidino­acetic acid‐κ2O:O′)­bis­[(nitrato‐κO)copper(II)]

The title compound, [Cu₂(NO₃)₂(C₃H₇N₃O₂)₄], forms a centrosymmetric dimer, with the two Cu²⁺ ions separated by 2.6525 (6) Å. The asymmetric unit contains a Cu atom coordinated to two guanidino­acetic acid ligands (via one carboxyl­ate O atom from each ligand) and to a nitrate group. The inversion centre in P generates the entire mol­ecule, in which each Cu atom is coordinated to four carboxyl­ate and to one nitrate O atom; ignoring the Cu—Cu separation, the geometry about each Cu atom is square pyramidal. The amino acid ligand is in the zwitterionic form. Strong N—H?O hydrogen bonds lead to a three‐dimensional supramolecular structure, in which the N?O distances are in the range 2.931 (4)–3.278 (3) Å, with N—H?O angles ranging from 128 to 170°.     

catena‐Poly­[[di­aqua­(isonicotinato‐O,O′)­europium(III)]‐di‐μ‐isonicotin­ato‐O:O′]

The title complex, [Eu(C₆H₄O₂)₃(H₂O)₂], has a double carboxyl­ate‐bridged infinite‐chain structure, with one chelating carboxyl­ate group on each Eu ion centre, which also binds to two water mol­ecules to yield an eight‐coordinate square‐antiprismatic geometry, with Eu—O bond lengths in the range 2.338 (3)–2.594 (3) Å. The pyridine N atoms of the isonicotinate groups do not coordinate to the Eu ions; instead, they direct the formation of Eu^III coordination polymers via hydrogen bonding with coordinated water mol­ecules.     

μ‐1,4‐Benzenedicarboxylato‐bis[trans‐aqua(1,4,8,11‐tetraazacyclotetradecane)nickel(II)] diperchlorate forms a three‐dimensional hydrogen‐bonded framework

The title compound, [Ni₂(C₈H₄O₄)(C₁₀H₂₄N₄)₂(H₂O)₂](ClO₄)₂, contains two independent octahedral Ni^II centres with trans‐NiN₄O₂ chromophores. The bridging benzene­dicarboxyl­ate ligand is bonded to the two Ni atoms, each via one O atom of each carboxyl­ate, while the other O atom participates in an intramolecular N—H?O hydrogen bond, forming an S(6) motif. The cations are linked to the perchlorate anions via O—H?O and N—H?O hydrogen bonds [O?O 2.904 (6) and 2.898 (6) Å; O—H?O 158 (6) and 165 (6)°; N?O 3.175 (7) and 3.116 (7) Å; N—H?O 168 and 166°] to form molecular ladders. These ladders are linked by further O—H?O and N—H?O hydrogen bonds [O?O 2.717 (6) and 2.730 (5) Å; O—H?O 170 (4) and 163 (6)°; N?O 3.373 (7) and 3.253 (7) Å; N—H?O 163 and 167°] to form a continuous three‐dimensional framework. The perchlorate anions both participate in three hydrogen bonds, and both are thus fully ordered.     

2‐Pyridone–tartronic acid (1/1), 3‐hydroxy­pyridinium hydrogen tartronate and 4‐hydroxy­pyridinium hydrogen tartronate

Tartronic acid forms a hydrogen‐bonded complex, C₅H₅NO·C₃H₄O₅, (I), with 2‐pyridone, while it forms acid salts, namely 3‐hydroxy­pyridinium hydrogen tartronate, (II), and 4‐hy­droxy­pyridinium hydrogen tartronate, (III), both C₅H₆NO⁺·C₃H₃O₅⁻, with 3‐hydroxy­pyridine and 4‐hydroxy­pyridine, respectively. In (I), the pyridone mol­ecules and the acid mol­ecules form R(8) and R(10) hydrogen‐bonded rings, respectively, around the inversion centres. In (II) and (III), the cations and anions are linked by N—H⋯O and O—H⋯O hydrogen bonds to form a hydrogen‐bonded chain. In each of (I), (II) and (III), an intermolecular hydrogen bond is formed between a carboxyl group and the hydroxyl group attached to the central C atom, and in (I), the hydroxyl group participates in an intramolecular hydrogen bond with a carbonyl group. No intermolecular hydrogen bond is formed between the carboxyl groups in (I), or between the carboxyl and carboxyl­ate groups in (II) and (III).     

trans‐Diaquabis(1H‐imidazole‐4,5‐di­carboxyl­ate‐κ2N3,O4)­manganese(II)

In the title compound, [Mn(C₅H₃N₂O₄)₂(H₂O)₂], the Mn^II atom lies on an inversion centre, is trans‐coordinated by two N,O‐bidentate 1H‐imidazole‐4,5‐di­carboxyl­ate monoanionic ligands [Mn—O = 2.202 (3) Å and Mn—N = 2.201 (4) Å] and two water mol­ecules [Mn—O = 2.197 (4) Å], and exhibits a distorted octahedral geometry, with adjacent cis angles of 76.45 (13), 86.09 (13) and 89.20 (13)°. The complete solid‐state structure can be described as a three‐dimensional supramol­ecular framework, stabilized by extensive hydrogen‐bonding interactions involving the coordinated water mol­ecules, the carboxy O atoms and the protonated imidazole N atoms of the imidazole‐4,5‐di­carboxyl­ate ligands.     

2‐Amino‐5‐chloro‐1,3‐benzoxazol‐3‐ium 2‐(3,4‐di­chloro­phenoxy)­acetate

The 1:1 organic salt of the title compound, C₇H₆ClN₂O⁺·C₈H₅Cl₂O₃^? or [(2‐ABOX)(3,4‐D)], comprises the two constituent mol­ecules associated by an R₂²(8) graph‐set interaction through the carboxyl­ate group of 3,4‐D across the protonated N/N sites of 2‐ABOX [N?O 2.546 (3) and 2.795 (3) Å]. Cation/anion pairs associate across an inversion centre forming discrete tetramers via an additional three‐centre hydrogen‐bonding association from the latter N amino proton to a phenoxy O atom [N?O 3.176 (3) Å] and a carboxyl­ate O atom [N?O 2.841 (3) Å]. This formation differs from the polymeric hydrogen‐bonded chains previously observed for adduct structures of 2‐ABOX with carboxyl­ic acids.     

Poly­[trans‐di­aqua­manganese(II)‐μ‐(3‐pyridine­carboxyl­ato‐N:O)‐μ‐(3‐pyri­dinecarboxyl­ato‐O:N)]

The title complex, [Mn^II(nic)₂(H₂O)₂]_n [nic is 3‐pyridine­carboxyl­ate (also called nicotinate), C₆H₄NO₂^?], has a two‐dimensional layer structure with the unique Mn atom on an inversion centre. In each layer, all nicotinate ligands are coordinated to Mn atoms in a bridging/bidentate mode, thus linking the {Mn^II(nic)₂(H₂O)₂} monomeric units together to form a dative‐bond‐based layered polymer. The intra‐layer hydrogen bonds involving all water mol­ecules and the carboxyl­ate groups may play an auxiliary part in stabilizing the layer. The layers are arranged in an ordered manner along the a axis through van der Waals forces so as to complete the solid‐state structure of the crystal.     

Bis(μ‐3‐nitrobenzene‐1,2‐dicarboxyl­ato)‐κ8O1,O2:O2,O3;O3,O2:O2,O1‐bis­[triaqua­(2‐carboxy‐3‐nitro­benzoato‐κ2O,O′)lanthanum(III)] dihydrate

The title compound, [La₂(C₈H₃NO₆)₂(C₈H₄NO₆)₂(H₂O)₆]·2H₂O, consists of dimeric units related by an inversion center. The two La^III atoms are linked by two bridging bidentate carboxyl­ate groups and two monodentate carboxyl­ate groups. Each La^III atom is nine‐coordinated by six O atoms from five different carboxyl­ate groups and three from water mol­ecules. Hydrogen bonds between the water mol­ecules and between the solvent water and a carboxyl­ate O atom are observed in the structure. In the crystal packing, there are slipped π–π stacking inter­actions between the parallel benzene rings. Both hydrogen‐bonding and π–π inter­actions combine to stabilize the three‐dimensional supra­molecular network.     

Amino­pyrimidine–carboxyl­(ate) interactions in trimethoprim maleate,an antifolate drug

In the title cocrystal, trimethoprim maleate [2,4‐di­amino‐5‐(3,4,5‐tri­methoxy­benzyl)­pyrimidin‐1‐ium maleate], C₁₄H₁₉­N₄O₃⁺·­C₄H₃O₄^?, the trimethoprim mol­ecule is protonated at N1. The carboxyl group of the maleate ion makes a specific double hydrogen bond of type N—H?O with the 2‐amino group and the protonated N1 atom of the trimethoprim cation which is similar to the carboxyl­ate–trimethoprim cation interaction observed in the complex of di­hydro­folate reductase with trimethoprim. The pyrimidine moieties of trimethoprim cations are centrosymmetrically paired through a pair of N—H?N hydrogen bonds involving the 4‐amino group and the pyridinium N3 atom of a symmetry‐related molecule. One of the O atoms at the maleate carboxyl­ate group bridges the 2‐­amino and 4‐amino groups on either side of the paired trimethoprim cations. The other O atom of the carboxyl­ate group forms an intramolecular O—H?O hydrogen bond with the carboxyl group. These characteristic hydrogen bonds result in infinite two‐dimensional aggregation of rings into a supramolecular ladder, which is further crosslinked through weak C—H?O interactions with methoxy groups of neighbouring trimethoprim mol­ecules to form a layered structure.     

(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.