Assembly of 3D coordination polymers from 2D sheets by [2+2] cycloaddition reaction.

The synthesis of three 2D interdigitated Zn(II) coordination polymers (CPs), by using three monotopic ligands containing C=C bonds, is reported. Among these, two CPs with 4spy (4-styryl pyridine) and 2F-4spy (a 2'-fluoro derivative of 4spy) ligands showed quantitative formation of cyclobutane rings, thus demonstrating a unique synthetic procedure to synthesize metal-organic frameworks (MOFs) by using this photochemical reaction. Interestingly, these compounds can also be synthesized by mechanochemical grinding procedures by using Zn(OAc)2. In contrast, Zn(NO3)2 did not yield the required product, unlike in the solution route. In addition, compounds with 4vpy (4-vinylpyridine), 4spy and 2F-4spy ligands created different units in the CPs; 4vpy and 2F-4spy furnished paddle wheel units, whereas 4spy yielded tetrahedral Zn(II) repeating units. Furthermore, the change in coordination geometry manifests in the photoluminescence properties, attributed to the difference in charge-transfer and ligand-centered fluorescent phenomenon.

7-(4-Fluoro-benzyl-amino)-2-phenyl-1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amine methanol disolvate.

The 1,2,4-triazolo[1,5-a][1,3,5]triazine system in the title compound, C(17)H(14)FN(7)·2CH(3)OH, is essentially planar, with an r.m.s. deviation of 0.0215 Å. The attached phenyl ring lies almost in the mean plane of the heterocyclic core [dihedral angle = 3.56 (4)°]. In the crystal, centrosymmetric inversion dimers connected via inter-molecular N-H⋯N hydrogen bonds between H atom of the primary amino group and the triazine N atom [R(2) (2)(8) graph-set motif] form sheets parallel to (010). A second set of dimers connected via N-H⋯F hydrogen bonds between the other H atom of the primary amino group and the F atom forms an R(2) (2)(24) graph-set motif linking the sheets. Methanol solvent mol-ecules are packed in channels running along the [010] direction.

Metal-organic frameworks containing a tetrapyridylcyclobutane ligand derived from isomerization reaction.

The rctt isomer of tetrapyridylcyclobutane prepared from the solid-state [2 + 2] cycloaddition reaction of [bpeH(2)] x 2 CF(3)CO(2) [bpe = 1,2-bis(4-pyridyl)ethene] undergoes isomerization reaction to the rtct isomer in 100% yield, and this tetrahedral tetrapyridyl ligand forms two metal-organic frameworks having ptt and pts topology.

N'-Acetyl-5-amino-1-methyl-1H-pyrazole-4-carbohydrazonamide dihydrate.

In the title compound, C(7)H(12)N(6)O·2H(2)O, the Z configuration of the hydrazone fragment is stabilized by an intra-molecular N-H⋯N hydrogen bond involving one of the amino groups. In the crystal structure, the hydrazonamide mol-ecules are connected via inter-molecular N-H⋯O=C hydrogen bonds, forming C(7) chains running along [010]. The chains form sheets parallel to the (01). The chains are cross-linked by water mol-ecules to form a three-dimensional hydrogen-bonded network.

4-Carbethoxy-1-[4-(N,N-dimethylamino)benzoyl]thiosemicarbazide.

The mol-ecular structure of the title compound, C(13)H(18)N(4)O(3)S, (systematic name: ethyl N-{2-[4-(dimethyl-amino)benzo-yl]hydrazinethio-carbon-yl}carbamate) is stabilized by intra-molecular N-H⋯O=C hydrogen bonding arranged in an S(6) graph-set motif. In the crystal, inversion dimers connected via inter-molecular N-H⋯S=C hydrogen bonds [R(2) (2)(8) graph-set motif] form sheets parallel to the (21) plane. Dimers are also formed by the mol-ecules via weak inter-molecular N-H⋯S=C hydrogen bonds [R(2) (2)(10) graph-set motif] connecting the sheets.

8-Methyl-2-[4-(trifluoro-meth-yl)phen-yl]-8H-pyrazolo-[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-amine methanol disolvate.

In the title compound, C(14)H(10)F(3)N(7)·2CH(4)O, the heterocyclic ring system is essentially planar (r.m.s. deviation = 0.009 Å) and makes a dihedral angle of 6.91 (8)° with the attached benzene ring. In the crystal, the main mol-ecules form centrosymmetric R(2) (2)(8) dimers via pairs of N-H⋯N hydrogen bonds between the amino groups and pyrimidine N atoms. One of the independent methanol mol-ecules and its inversion equivalent are linked to the dimers via O-H⋯N and N-H⋯O hydrogen bonds, forming R(4) (4)(16) graph-set motifs. The dimers along with the hydrogen-bonded methanol mol-ecules are stacked along the a axis, with π-π inter-actions between the pyrazole and triazole rings [centroid-centroid distance = 3.4953 (10) Å].

4-Amino-2,8-dimethyl-6H-pyrimido[1,2-a][1,3,5]triazin-6-one.

In the title compound, C(8)H(9)N(5)O, the mean planes through the pyrimidine and triazine rings form a dihedral angle of 2.83 (16)°. The amino group adopts a trigonal-planar configuration and forms an intra-molecular resonance-assisted N-H⋯O=C hydrogen bond with the carbonyl group. In the crystal, mol-ecules are linked via inter-molecular N-H⋯N hydrogen bonds into chains of C(2) (2)(6)[R(2) (2)(6)] motif. The molecules form two types of sheet parallel to (201) and (01), respectively.

N-Carbethoxy-N'-(3-phenyl-1H-1,2,4-triazol-5-yl)thiourea.

The title compound {systematic name: ethyl N-[N-(3-phenyl-1H-1,2,4-triazol-5-yl)carbamothio-yl]carbamate}, C(12)H(13)N(5)O(2)S, exists in the 3-phenyl-5-thio-ureido-1H-1,2,4-triazole tautomeric form stabilized by intra-molecular hydrogen bonding between the endocyclic NH H atom and the thio-ureido S atom. The mol-ecular structure is also stabilized by intra-molecular N-H⋯O=C hydrogen bonds arranged in an S(6) graph-set motif within the carbethoxy-thio-urea moiety. The mean planes of the phenyl and 1,2,4-triazole rings make a dihedral angle of 7.61 (11)°. In the crystal, the mol-ecules form two types of inversion dimers. Inter-molecular hydrogen bonds are arranged in R(2) (2)(6) and R(2) (2)(8) graph-set motifs, together forming a network parallel to (111).

N-Carbethoxy-N'-[3-(4-methylphenyl)-1H-1,2,4-triazol-5-yl]thiourea.

THE TITLE COMPOUND, [SYSTEMATIC NAME: ethyl ({[3-(4-methylphenyl)-1H-1,2,4-triazol-5-yl]amino}carbonothioyl)carbamate], C(13)H(16)N(5)O(2)S, exists in the 3-aryl-5-thio-ureido-1H-1,2,4-triazole tautomeric form. The mol-ecular structure is stabilized by intra-molecular hydrogen bonding (N-H⋯S=C between the endocyclic N-bound H atom and the thio-ureido S atom, and N-H⋯O=C within the ethoxy-carbonyl-thio-urea unit), both arranged in an S(6) graph-set motif. The mean planes of the phenyl and 1,2,4-triazole rings make a dihedral angle of 6.59 (10)°. In the crystal structure, the mol-ecules form two types of centrosymmetric dimers connected by inter-molecular hydrogen bonds; in the first, the N-NH triazole sides of two mol-ecules are connected [R(2) (2)(6) graph-set motif] and the second is an N-H⋯S=C inter-action between the imide H atoms and the thio-carbonyl S atoms [R(2) (2)(8) graph-set motif]. Together, they form a network parallel to the (111) plane.

A monoclinic polymorph of N-eth-oxy-carbonyl-N'-(3-phenyl-1H-1,2,4-triazol-5-yl)thio-urea.

The title compound, C(12)H(13)N(5)O(2)S {systematic name: ethyl N-[N-(3-phenyl-1H-1,2,4-triazol-5-yl)carbamothio-yl]carbamate}, is a monoclinic polymorph (space group P2(1)/c) which crystallizes with three similar independent mol-ecules in the asymmetric unit. The triazole ring makes dihedral angles of 6.6 (2), 8.4 (2) and 10.6 (2)° with the phenyl ring in the three independent molecules. The structure was previously reported [Dolzhenko et al. (2010a ▶). Acta Cryst., E46, o425] as a triclinic polymorph crystallizing in space group P. Mol-ecules in both polymorphs possess two S(6) rings generated by intra-molecular N-H⋯S and N-H⋯O hydrogen bonds, resulting in similar mol-ecular geometries. However, the two polymorphs differ in the crystal packing. In contrast to the dimers of the triclinic polymorph, mol-ecules of the monoclinic polymorph are connected by inter-molecular N-H⋯S and N-H⋯N hydrogen bonds, forming pseudosymmetric trimers arranged in sheets parallel to (302).

4,4-Dimethyl-3,4-dihydro-pyrido[2',3':3,4]pyrazolo-[1,5-a][1,3,5]triazin-2-amine ethanol monosolvate.

In the title compound, C(10)H(12)N(6)·C(2)H(5)OH, the planarity of the heterocyclic system is slightly distorted at the triazine ring (r.m.s. deviation = 0.1191 Å), which adopts a conformation best described as inter-mediate between a flattened twisted boat and a half-boat with the tertiary Csp(3) atom at the bow. In the crystal, mol-ecules form centrosymmetric dimers connected by N⋯H-O and O⋯H-N hydrogen bonds between the amino group H atom, the ethanol solvent mol-ecule and the triazine N atom, making an R(4) (4)(12) graph-set motif. The other H atom of the amino group and the H atom on the endocyclic N atom form N⋯H-N hydrogen bonds with the N atoms of the pyrazole and pyridine rings, respectively, linking the mol-ecules into C(7)C(7) chains with the R(2) (2)(8) binary graph-set motif running along [010].

2-Phenyl-7-(4-pyridyl-methyl-amino)-1,2,4-triazolo[1,5-a][1,3,5]triazin-5(4H)-one.

In the title compound, C(16)H(13)N(7)O, the 1,2,4-triazolo[1,5-a][1,3,5]triazine heterocyclic system is essentially planar (r.m.s. deviation = 0.0375 Å). The attached benzene ring lies almost in the mean plane of 1,2,4-triazolo[1,5-a][1,3,5]triazine [dihedral angle = 1.36 (23)°], while the pyridine ring is turned out of this plane by the amino-methyl bridge [dihedral angle = 69.22 (9)°]. The amino group H atom is involved in intra-molecular hydrogen bonding with a triazole N atom. In the crystal, mol-ecules are connected via C(=O)NH⋯N hydrogen bonds into C(11) chains parallel to [100]. The amino group H atom acts as a hydrogen-bond donor, forming an NH⋯O=C hydrogen bond with the carbonyl O atom, which links the mol-ecules into C(6) chains running along [011] and [01].

One-pot oxidation and protonation of a bridging sulfide and rare crystallographic evidence of a coordinated [SO] complex in [Pt2(micro-S2O2H)(PPh3)4]+.

One-pot oxidation and protonation of the sulfide bridging complex [Pt(2)(micro-S)(2)(PPh(3))(4)] can be promoted by lanthanide or scandium compounds, leading to the isolation of [Pt(2)(micro-S(2)O(2)H)(PPh(3))(4)](+); crystallographic elucidation confirmed sulfide mono-oxygenation without S-S bonding to give formally [SO](2-) in the form of an [SOHOS](3-) overhead bridge.

Structures of copper complexes of the hybrid [SNS] ligand of bis(2-(benzylthio)ethyl)amine and facile catalytic formation of 1-benzyl-4-phenyl-1H-1,2,3-triazole through click reaction.

A hybrid ligand, bis(2-(benzylthio)ethyl)amine (SNS), with an amine and two thioether donors reacts with Cu(II) to give mononuclear [CuCl(2)(SNS)] (1), [CuBr(2)(SNS)] (2), [Cu(OTf)(2)(SNS)(OH(2))] (3), and an one-dimensional Cu(I) coordination polymer [Cu(2)I(2)(SNS)](n) (4). All complexes have been characterized by single-crystal X-ray diffraction analysis, and 1-3 were studied by EPR analysis at room temperature. Complexes 1 and 2 are penta-coordinated with a distorted square pyramidal metal supported by a tridentate SNS ligand on the basal plane. Complex 3 shows a tetragonally distorted octahedral sphere with two trans and weakly bonding monodentate triflates. A 12-membered ring in the solid lattice is formed by intermolecular H-bonding among the coordinated triflate and aqua ligands from four neighboring molecules. Complex 4, the only Cu(I) in this series, shows a coordination polymer chain [Cu(4)I(4)](n) comprising tetrahedral Cu(I) centers stitched by the SNS ligand in a unique bridge-chelate mode in the form of a helix. All four complexes are catalytically active at room temperature in a copper-catalyzed azide-alkyne cycloaddition (CuAAA) three-component click reaction of benzyl chloride, sodium azide, and phenylacetylene in an aqueous MeCN mixture to give good isolated yields of 1-benzyl-4-phenyl-1H-1,2,3-triazole, without the use of a base or reducing agent.

2-Amino-4-(4-bromo-phen-yl)-8-trifluoro-methyl-3,4-dihydropyrimido[1,2-a][1,3,5]triazin-6(5H)-one.

The title compound, C(13)H(9)BrF(3)N(5)O, crystallizes with two independent mol-ecules in the asymmetric unit. The pyrimidine rings of the mol-ecules are planar [maximum deviations 0.053 (3) and 0.012 (3) Å], while the triazine rings adopt flattened half-boat conformations with the p-bromo-phenyl rings in the flagpole positions. The crystal packing is stabilized by a three-dimensional network of inter-molecular N-H⋯N, N-H⋯O and N-H⋯F hydrogen bonds.

(4Z,6Z,12Z,14Z)-2,10-Dimethyl-2,8,10,16-tetra-hydro-dipyrazolo[3,4-e:3',4'-l][1,2,4,8,9,11]hexa-azacyclo-tetra-decine-4,12-diamine.

The title compound, C(12)H(16)N(12), is a centrosymmetric mol-ecule which comprises of a hexa-aza[14]annulene macrocyclic ring fused with two pyrazole rings. The macrocyclic ring is essentially planar, with an r.m.s. deviation of 0.0381 Å. The electron pairs of the amino groups are delocalized with the conjugated system of the macrocycle. Strong intra-molecular N-H⋯N hydrogen bonds arranged in an S(2) (2)(10) graph-set motif are present in the macrocyclic ring. In the crystal, the amino groups act as donors for inter-molecular N-H⋯N inter-actions with the N atoms of the heterocyclic system, forming a network of two types of extended chains oriented parallel to the [101] and [011] directions. The crystal packing is also stabilized by weak inter-molecular C-H⋯N hydrogen bonds formed between pyrazole C-H groups and N atoms of the macrocyclic ring, running in the [10] direction.

4-Hydrazino-1-methyl-pyrazolo[3,4-d]pyrimidine.

The title compound, C(6)H(8)N(6), crystallizes as an N-H⋯N hydrogen-bond-linked dimer of two almost identical mol-ecules in the asymmetric unit. Both of the mol-ecules are almost planar (rms deviations of 0.0186 and 0.0296 Šin the two molecules) and their hydrazino groups are turned towards the pyrazole rings. The dimers are arranged into chains via inter-molecular N-H⋯N hydrogen bonds between the hydrazino groups and the N atoms of the pyrimidine rings of both types of the mol-ecules, linking the mol-ecules into a C(7) graph-set motif along [100]. The methyl groups and the N atoms of the pyrazole rings form weak C-H⋯N hydrogen bonds, which connect chains of the dimers in a C(4) motif parallel to [100].

7-Dimethyl-amino-2-phenyl-1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amine methanol solvate.

7-Dimethyl-amino-2-phenyl-1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amine crystallized with one mol-ecule of methanol to give the title compound, C(12)H(13)N(7)·CH(3)OH. The triazolo[1,5-a][1,3,5]triazine heterocyclic core is essentially planar as are both amino groups that are involved in π-electron delocalization with the triazolo[1,5-a][1,3,5]triazine nucleus. The methyl groups of the dimethyl-amino fragment are involved in the formation of weak intra-molecular C-H⋯N hydrogen bonds with the N atoms of the heterocyclic system. The crystal packing is stabilized by inter-molecular N-H⋯N hydrogen bonds between the triazolo[1,5-a][1,3,5]triazine mol-ecules. The methanol solvent mol-ecule also participates in the formation of the crystal structure via inter-molecular O-H⋯N, N-H⋯O and weak C-H⋯O hydrogen bonds, linking the layers of triazolo[1,5-a][1,3,5]triazine mol-ecules.

3-Pyridin-2-yl-1H-1,2,4-triazol-5-amine.

In the title compound, C(7)H(7)N(5), the non-H atoms are almost coplanar (r.m.s. deviation = 0.050 Å), with the N atom of pyridine ring oriented to the N-N(H) side of the 1,2,4-triazole ring. The mean planes of the pyridine and 1,2,4-triazole rings form a dihedral angle of 5.58 (7)°. The N atom of the amino group adopts a pyramidal configuration. The mol-ecules are linked into a two-dimensional network parallel to (10) by N-H⋯N hydrogen bonds.

3-Phenyl-1H-1,2,4-triazol-5-amine-5-phenyl-1H-1,2,4-triazol-3-amine (1/1).

In the title compound, C(8)H(8)N(4)·C(8)H(8)N(4), two tautomers, viz. 3-phenyl-1,2,4-triazol-5-amine and 5-phenyl-1,2,4-triazol-3-amine, are crystallized together in equal amounts. The 3-phenyl-1,2,4-triazol-5-amine mol-ecule is essentially planar; the phenyl ring makes a dihedral angle of 2.3 (2)° with the mean plane of the 1,2,4-triazole ring. In the 5-phenyl-1,2,4-triazol-3-amine tautomer, the mean planes of the phenyl and 1,2,4-triazole rings form a dihedral angle of 30.8 (2)°. The π-electron delocalization of the amino group with the 1,2,4-triazole nucleus in the 3-phenyl-1,2,4-triazol-5-amine mol-ecule is more extensive than that in the 5-phenyl-1,2,4-triazol-3-amine tautomer. The mol-ecules are linked into a two-dimensional network parallel to (100) by N-H⋯N hydrogen bonds.