Curved crystal morphology, photoreactivity and photosalient behaviour of mononuclear Zn(II) complexes.

A dramatic effect of crystal morphology, photoreactivity and photosalient property is observed in a zinc(II) complex due to solvent effects and fluorine substitution at the backbone of the ligand. Of the two crystal forms with a 3-fluoro derivative, one yielded a curved morphology of single crystals and the second form shows photoreactivity in the solid state, whereas crystals of the 2-fluoro derivative pop during the [2 + 2] photocycloaddition reaction. This is the first report documenting curved single crystals of metal complexes obtained naturally during crystallization, although such bent crystals have been observed in extended solids naturally, or bent by mechanical force or by UV irradiation.

Molecular Scissoring: Facile 3D to 2D Conversion of Lanthanide Metal Organic Frameworks Via Solvent Exfoliation.

Five lanthanide MOFs with pcu topology have been exfoliated into nanoplatelets of two-dimensional structures via sonication in the dimethylacetamide solvent. These nanosheets are fluorescent under two-photon excitation dominated by the ligand, indicating energy upconversion ability.

Thermal cleavage of cyclobutane rings in photodimerized coordination-polymeric sheets.

Three coordination polymers, [Cd(2)(pvba)(2)(tbdc)(dmf)(2)] (1), [Co(2)(pvba)(2)(tbdc)(dmf)(2)(H(2)O)(2)] (2), and [Ni(2)(pvba)(2)(tbdc)(dmf)(2)(H(2)O)(2)] (3) (H(2)tbdc = 2,3,5,6-tetrabromobenzenedicarboxylic acid, Hpvba = trans-2-(4'-pyridyl)vinylbenzoic acid), were synthesized by solvothermal methods. The solid-state structures of compounds 1 and 2 were determined by X-ray crystallography. In compounds 1 and 2, the bimetallic cores acted as secondary building units that connected the tbdc ligands in one direction and a pair of pvba ligands, which were aligned in a head-to-tail parallel manner, in the orthogonal direction to form sheet structures.

Photoreactive gold(I) macrocycles with diphosphine and trans,trans-muconate ligands.

A pair of trans,trans-muconate ligands have been successfully aligned in two novel Au(I) macrocycles by design from phosphino metal precursors that undergo photochemical cycloaddition reactions quantitatively, resulting in the formation of cyclooctadiene derivatives.

Role of anions in the synthesis of cyclobutane derivatives via [2 + 2] cycloaddition reaction in the solid state and their isomerization in solution.

trans-3-(4'-Pyridyl)acrylic acid (4-PA) is inert to photodimerization reaction both in solution and solid state. It is made photoreactive by forming salts with various acids. The anions of these salts play a key role in directing the packing of 4-PAH(+) in the solid state.

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.

A novel heteroleptic paddlewheel diruthenium bicyclic guanidinate complex: synthesis, structure, and scope.

A novel paddlewheel or 'lantern' heteroleptic diruthenium guanidinate complex Ru(2)(TBO)(2)(OAc)(2)Cl x 3MeCN (1 x 3MeCN) was synthesized and structurally characterized. Compared with a known tetra-substituted di-ruthenium guanidinate complex Ru(2)(TBD)(4)Cl, 1 revealed structural dissimilarities with internal twisting.

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.

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.

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.

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.

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.

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.

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).

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.

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.

Anion-controlled stereoselective synthesis of cyclobutane derivatives by solid-state [2 + 2] cycloaddition reaction of the salts of trans-3-(4-pyridyl) acrylic acid.

Two stereoisomers of cyclobutane derivatives with pyridyl and carboxylic acid functionalities have been stereoselectively synthesized by a solid-state photochemical [2 + 2] cycloaddition reaction in quantitative yields. The head-to-head and head-to-tail parallel orientations of the monomers, required to obtain these two isomers, have been controlled by the anions present in the salts. The photoinert behavior of these salts in solution signifies the importance of the solid-state synthesis of these cyclobutane derivatives.

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.

(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.

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.

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-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.

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.

Cyclopalladation of the prochiral (di-tert-butyl)(diphenylmethyl)phosphine: kinetic lability of the corresponding (+)-phosphapalladacyclic Pd-C bond and the reluctance of the phosphine to bind in a monodentate fashion.

The ortho palladation of prochiral (di-tert-butyl)(diphenylmethyl)phosphine proceeded readily to give rise to the dimeric complex, di-mu-chlorobis{[(phenyl)(di-tert-butylphosphino)methyl]phenyl-C2, P}dipalladium(II). The (S,S)-(+)-dimer was subsequently obtained by optical resolution with sodium (S)-prolinate. The absolute configuration of the optically resolved (+)-dimer was concluded from the X-ray diffraction studies of the derivatized O,O-acetylacetonate complex.