2-(1H-Tetra­zol-5-yl)benzonitrile

The title compound, C8H5N5, was synthesized from phthalonitrile. The benzonitrile and tetra­zole rings are inclined at a dihedral angle of 37.14 (11)°. In the crystal structure, inter­molecular N—H⋯N hydrogen bonds link the tetra­zole rings of adjacent mol­ecules, forming chains along the a axis

A quantum-chemical study on 3,3'-bi(4H-1,2,4-triazole)

1246-125

Automatic Description Generation from Images: A Survey of Models, Datasets, and Evaluation Measures

Automatic description generation from natural images is a challenging problem that has recently received a large amount of interest from the computer vision and natural language processing communities. In this survey, we classify the existing approaches based on how they conceptualize this problem, viz., models that cast description as either generation problem or as a retrieval problem over a visual or multimodal representational space. We provide a detailed review of existing models, highlighting their advantages and disadvantages. Moreover, we give an overview of the benchmark image datasets and the evaluation measures that have been developed to assess the quality of machine-generated image descriptions. Finally we extrapolate future directions in the area of automatic image description generation.Comment: Journal of Artificial Intelligence Research 55, 409-442, 201

A quantum-chemical study on the electrophilic addition of chlorine and bromine to bicyclo [2. 2. 2] octa-2,5-diene

303-306The molecular complexes of bicyclo [2. 2. 2] octa-2,5-diene with chlorine and bromine have been investigated using AM1 semiempirical method. The geometric parameters and stabilisation energies related to the complexes have been calculated. The exo and endo adducts are found to be nearly isoenergetic. The greater stearic repulsions in the exo complex are apparently compensated by increased electronic stabilisation. The cationic intermediates of the electrophilic addition of chlorine and bromine to bicyclo [2. 2. 2] octa-2,5-diene have been investigated by MNDO and ab initio methods. The results obtained reveal that the bridged endo-halogenium cation is relatively more stable than the bridged exo-halogenium cation for both chlorine and bromine. The rearranged cations have been found to be the most stable ones among the cationic intermediates formed in the reaction. It is plausible that the ionic addition reactions proceed via the most stable cations. Essentially, the rearranged addition products are predicted to form in the ionic addition reactions of ch lorine and bromine to bicyclo [2. 2. 2] octa-2,5-diene. </span

A quantum-chemical study on bi(1,2,3-triazole) molecule

413-417The conformational analysis of 4,4'-bi(1H-I ,2,3-triazole)A, 5,5'-bi (1<i style="mso-bidi-font-style: normal">H-1,2,3-triazole) B and 5,5'-bi (2H-1,2,3 -triazole) C tautomers of flexible bi(1,2,3-triazole) molecule containing various reaction centres has been performed by semiempirical methods AM1 and PM3. Furthermore, electronic properties of the tautomers and the effect of conformational changing on their electronic properties have also been investigated. In order to determine the orientation sites of proton attacks at the bitriazole system, molecular electrostatic potentials of the tautomers have been calculated. Conformations and electronic properties of the monoprotonated species of the tautomers have also been studied. Proton affinity of the tautomers has been calculated for different nitrogens, and possible protonation centres determined. Moreover, the complex formation ability of the tautomers with metal cations has been evaluated and discussed.</span

A quantum-chemical investigation on 3,4'-bi(4H-1,2,4-triazole)

728-733The conformational analysis of 3,4¢-bi(4H-1,2,4-triazole) molecule has been performed using the semiempirical methods MNDO, AMI and PM3, and the stable conformations, the rotational barriers and geometric parameters have been determined. The total energies, heats of formation, dipole moments, ionization potentials, full atomic charges, energies of frontier molecular orbitals (EHOMO and ELUMO) and electron densities have been calculated and discussed, In order to determine the orientation centers of proton attacks at the 3,4' -bitriazole system, the molecular electrostatic potential (MESP) of the molecule has been also calculated, The conformational analyses of mono- and diprotonated species have also been performed by AM1 aand PM3 routes and their stable conformations determined. The proton affinity for the different nitrogens of the 3,4' -bitriazole molecule has been calculated using AM1 and PM3 methods and more basic centers have been determined. Furthermore, the complex formation ability of the molecule with metal cations is also discussed. The electronic properties of the complexes formed by Mg2+ and Fe2+ ions have been investigated using PM3 and ZINDO/1 methods, and the stabilities of these complexes are discussed

Synthesis of some 4-(arylmethylamino)-4, 5-dihydro-1<i>H</i>-1 ,2,4-triazol-5-ones

1527-1530A series of 3-alkyl-4-(arylmethyleneamino)-4,5-dihydro-1 H-1,2,4-triazol-5-ones 2 are obtained and reduced with NaBH4 selectively to afford 3-alkyl-4-(arylmethylamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones 3. Compounds of type 2 have recently described as a new class of antitumor agent. Thus, 15 new compounds have been synthesized and characterized by elemental analyses, 1H NMR, IR and UV spectra. Three of these compounds have been screened for their antitumor activities and found weak cytostatic activity in them

Data-driven image captioning with meta-class based retrieval

Automatic image captioning, the process cif producing a description for an image, is a very challenging problem which has only recently received interest from the computer vision and natural language processing communities. In this study, we present a novel data-driven image captioning strategy, which, for a given image, finds the most visually similar image in a large dataset of image-caption pairs and transfers its caption as the description of the input image. Our novelty lies in employing a recently' proposed high-level global image representation, named the meta-class descriptor, to better capture the semantic content of the input image for use in the retrieval process. Our experiments show that as compared to the baseline Im2Text model, our meta-class guided approach produces more accurate descriptions