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2,4-Diamino-6-phenyl-1,3,5-triazine-1-ium nitrate (LH)(NO3) crystallises in the triclinic centrosymmetric space group P with an intriguing high number of crystallographically unique salt-like adducts (Z′ = 8) and a total number of ionic species (Z′′ = 16) in the asymmetric unit. The organic cations and nitrate anions are combined into two similar H-bonded neutral tapes strengthening by 20 unique NH⋯O and NH⋯N hydrogen bonds each. Hydrogen bonds are ordered into a repeated sequence of homo- and hetero-synthons, R22(8)R33(10)R22(8)R22(8)R24(8)R33(10) as ring motifs. The paired cations form R22(8) ring motifs through base pairing of N–H⋯N hydrogen bonds. All other patterns include both cations and anions. In the crystal structure, the compromise between the tapes rigidity provided by the multiple directional H-bonds within the tapes and packing preferences is reached through the restricted internal rotation about the C–C bond joining the phenyl and triazine cycles in the 2,4-diamino-6-phenyl-1,3,5-triazine-1-ium cations. The decisive impact of NH⋯O(N) hydrogen bonds in the crystal stability and distribution of other types of intermolecular interactions was estimated by Hirshfeld surface analysis. The undertaken CSD overview for the metal-free L-based crystals reveals the exclusivity of the title compound from the viewpoint of the high reported Z′/Z′′ values and the number of unique hydrogen bonds.

Five new transition metal coordination compounds based on pyrazinecarboxamide and dicarboxylic acids have been prepared, and their structures have been characterized by IR spectroscopy and single crystal X-ray diffraction. The crystalline solids include one dinuclear compound [Cu2(mal)2(pca)2(H2O)2]·H2O (1), three one-dimensional coordination polymers [M(mal)(pca)(H2O)]n M = Co(II), Zn(II) (2, 3), [Cu2(CH3COO)4(pca)]n (4) and one two-dimensional coordination polymer [Cd(bdc)(pca)(H2O)]n (5), where pca = pyrazinecarboxamide, H2mal = malonic acid and H2bdc = 1,4-benzenedicarboxylic acid. The pca coordinates to the metal centers as a neutral ligand in chelating (1, 2, 3), bidentate bridging (4) and monodentate modes (5), while the bidentate acetate, malonate and benzenedicarboxylato anionic ligands provide extensions of structures. The new compounds 1, 3 and 5 reveal violet and ultraviolet luminescence upon excitation with ultraviolet light.

New coordination polymers are reported. All polymers were prepared from a blend of four dicarboxylic acids, three neutral nicotinamide ligands, and Zn(II) or Cd(II) salts. The acids included: malonic (H2mal), succinic (H2suc), adipic (H2adi), and 1,4-benzenedicarboxylic (H2bdc) acids, with all of them varying in length and rigidity of the carbon skeletons. The neutral ligands included two positional isomers, isonicotinamide (iso-nia) and nicotinamide (nia), and a nia thio-analogue, thionicotinamide (S-nia). The preparation resulted in eight Cd(II) and four Zn(II) coordination polymers: [Cd2(suc)(sucH)2(nia)4]n (1), {[Cd(suc)(nia)3]·H2O·dmf}n (2), {[Cd(adi)(iso-nia)2]·dmf}n (3), [Cd(adi)(iso-nia)2]n, (4), {[Zn(mal)(iso-nia)(H2O)]·dmf}n (5), {[Cd(mal)(iso-nia)(H2O)]·dmf}n (6), {[Zn(mal)(nia)(H2O)]·dmf}n (7), {[Cd(mal)(nia)(H2O)]·dmf}n (8), {[Zn(mal)(S-nia)(H2O)]·dmf}n (9), {[Zn(bdc)(nia)2]·dmf}n (10), {[Cd(bdc)(nia)2]·dmf}n (11), and nicotinamide-free {[Cd(bdc)(H2O)2(dmf)]·dmf}n (12). Compounds 1–4 and 12 consist of one-dimensional arrays, while compounds 5–11 are two-dimensional coordination arrays. The coordination cores in 1, 3, 4, 10, and 11 present {M2(COO)2} (M = Zn, Cd) binuclear clusters, while the networks of 2, 5–9 and 12 are built on mononuclear metal nodes with nicotinamide ligands acting as double or single pillars. The structure-confirmed single crystal to single crystal transformation of 3 into 4 was detected and reported. While 1 and 4 are solvent-free apohosts, the remaining solids acted as hosts of water and dmf solvent which are accommodated in the crystal lattices as coordinated ligands or lattice solvents. The new solids were characterized by IR spectroscopy, thermogravimetric analysis, and single-crystal and powder X-ray diffraction methods. The luminescence properties of six as-synthesized coordination polymers and of some activated products are reported. The influence of the metal, ligand, and solvent on tuning the structures and emission properties was monitored, and the most impressive effects were interpreted with the help of TD-DFT computations.

Four Cu(II)-based neutral coordination polymers, 1D {[Cu(isonia)2(adi)(dmf)].0.5H2adi}n (1), 2D {[Cu(isonia)2(adi)](H2O.H2adi)}n (2), 1D {[Cu(pic)(CH3COO)(bpe)].H2O}n (3), and 2D [Cu2(pic)2(CH3COO)2(bpy)]n (4) with biocompatible molecules: isonicotinamide (isonia), pyridine-2-carboxylic (picolinic, Hpic) and adipic (H2adi) acids and 1,2-bis(4-pyridyl)-ethane (bpe) and 4,4′-bipyridine (bpy) as neutral linkers are reported. The polymer extension in 1 and 2 is reached via bidentate bridging adi anions with isonia ligands as single (1) and double (2) pillars. 1D and 2D coordination arrays are associated in elegant 3D H-bonded networks via interplay of robust amide(isonia)…amide(isonia) homosynthon and NH…O(COO–) side interactions. In 3 the pic residue coordinates in a chelate mode and forms the five-membered [Cu(pic)] corner fragment. The structure expansion occurs via bidentate-bridging bpe neutral linker registered in a coordination wire as different conformers thus providing long (Cu-bpe)6 crystallographically unique chain fragment. Oppositely, in 4 the pic residue acts in a bidentate chelate bridging mode and gives rise to the 2D coordination array. The bpy trapping between each two Cu(II) atoms, does not participate in further structure extension. The decisive impact of amido-group of isonia ligand in structure rigidification and retention of protic H2adi and water guest molecules is demonstrated. The gradual decrease of guest’s capacity correlates with an increased liphophilicity of 3 and 4 comparing with 1 and 2.

The reaction of a ditopic ligand, 1,4-benzenedicarboxylic acid (H 2 bdc) with Co(CH 3 COO) 2 ·4H 2 O in solution resulted in a solvent-rich layered coordination polymer with the composition {[Co 2 (μ 2 -OH 2 )(bdc) 2 (dmf) 2 (H 2 O) 2 ]·(dmf)·3(H 2 O)} n ( 1 ) whose crystal structure was determined by single crystal X-ray diffraction. The compound is built on the binuclear {Co 2 (μ 2 -OH 2 )(COO) 2 } metal clusters, where each Co(II) atom is coordinated by six oxygen atoms in a distorted octahedral arrangement. The crystal lattice of 1 hosts the dmf and water solvent molecules via the OH⋯O hydrogen bonding with coordination network. The easy destruction of the crystals due to the partial solvent loss occurs rapidly in ambient conditions and is confirmed by the TGA data.

Six coordination compounds based on 4,4′-diaminodiphenylmethane (dadpm) and different salts (acetates, nitrates and perchlorates) of four (Ni, Co, Zn, Cd) transition metals have been prepared and characterized by IR spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction methods. The crystalline solids include four monomers: [Co(dadpm)2(CH3COO)2(H2O)2] (1), [Cd(dadpm)2(CH3COO)2(H2O)2] (2), [Zn(dadpm)4(H2O)2](NO3)2(H2O)2 (3), [Ni(dadpm)3(dmf)(H2O)2](ClO4)2(dadpm)(H2O) (4), and two one-dimensional coordination polymers: {[Cd(dadpm)2(H2O)(ClO4)](ClO4)}n (5) and {[Cd(dadpm)4](ClO4)2}n (6). The transition metals used in this study accommodate two, three, four and six dadpm ligands in the coordination cores. The luminescence properties for six coordination compounds are reported.

Heating of a pink two-dimensional Co(II) coordination network {[Co2(μ2-OH2)(bdc)2(S-nia)2(H2O)(dmf)]·2(dmf)·(H2O)}n (1) built from 1,4-benzenedicarboxylic acid (H2bdc) residues and thionicotinamide (S-nia) ligands initiates a single-crystal-to-single-crystal transition accompanied by removal of both coordinated and co-crystallized solvents. In the dry blue form, [Co(bdc)(S-nia)]n (dry_1), the Co(II) centers changed from an octahedral to a square pyramidal configuration.

A new three-dimensional coordination polymer, {[Co(μ2-H2O)(bdc)(H2O)(dmf)]·0.5H2O}n (1), was obtained as a by-product in the synthesis of the laminar solid {[Co2(μ2-H2O)(bdc)2(S-nia)2(H2O)(dmf)]·(dmf)2·H2O}n (2) (where H2bdc = 1,4-benzenedicarboxylic acid, S-nia = thionicotinamide, dmf = N,N′-dimethylformamide). The three-dimensional network in 1 is organized of Co(II) atoms in O6 octahedral coordination environments separated by μ2-water molecules in coordination chains. The bdc2− anions coordinate in monodentate mode and also act as bridging ligands that extend the structure in two other directions. The coordination cores of two crystallographically different Co(II) atoms are completed by either two dmf or two water molecules. The rhombohedral open channels contain water molecules. The evacuation of solvents from 1 occurs as a single crystal to single crystal transformation and results in MOF-71, [Co(bdc)(dmf)]n, whose structure was confirmed by single crystal X-ray diffraction.

Dinucleartetracarboxylato-bridged copper(II)solvato-morph [Cu2(OAc)4(ina)2] •2dmso was prepared and studied by IR spectroscopy, TGA analysis and single crystal X-ray method. Cu(II) ions are bridged by four syn,syn-η1:η1:μ carboxylates, showing a paddle-wheel cage-type with a square-pyramidal geometry.

Five new coordination polymers, {[Co(OAc)2(bpe)(H2O)]·0.5(dmf)}n (1), {[Co(bpy)2(H2O)4][Co(tfa)(bpy)2(H2O)3](tfa)3·1.5(bpy)}n (2), [Co(tfa)2(dps)4]n (3), {[Co(tfa)2(bpe)4]·H2O}n (4), and [Co(tfa)2(bpp)4]n (5) (where AcO– = CH3CO2–; tfa– = CF3CO2–; bpy = 4,4′-bipyridine; bpe = 1,2-bis(4-pyridyl)ethane; bpp = 1,3-bis(4-pyridyl)propane; dps = 4,4′-dipyridyl sulfide; dmf = N,N′-dimethylformamide) were synthesized by the reactions of Co(OAc)2·4H2O and Co(tfa)2·4H2O with different dipyridyl ligands and characterized by elemental analysis, IR spectra, and X-ray single-crystal diffraction. Compound 1 exhibits extended two-dimensional (2D) networks through the bridging AcO– and bpe ligands. The polymeric motifs in 2–5 are exclusively based on bipyridine-type ligands and results in 1D cationic chains in 2, similar charge-neutral double tapes in 3 and 4, and a 2D polymeric network in 5. In 2–5, the tfa anions coordinate to the Co(II) center in a monodentate mode. An impact of the anion’s fluorination on coordination...

In the title compound, [Zn(C6H4NO2)2(H2O)2]·0.5C3H7NO, the Zn(II) ion is coordinated in a distorted octa-hedral N2O4 environment by two N,O-chelating pyridine-2-carboxyl-ate ligands and two cis water mol-ecules. The chelating pyridine-2-carboxyl-ate ligands create two five-membered Zn/N/C/C/O rings, which form a dihedral angle of 86.4 (2)°. In the crystal, O-H⋯O hydrogen bonds link the complex mol-ecules into a two-dimensional network parallel to (100). The di-methyl-formamide solvent mol-ecule is disordered about a twofold rotation axis.