The atom-bond connectivity (ABC) index and geometric-arithmetic (GA) index are two well-studied topological indices, which are useful tools in QSPR and QSAR investigations. In this paper, we first obtain explicit formulae for the expected values of ABC and GA indices in random spiro chains, which are graphs of a class of unbranched polycyclic aromatic hydrocarbons. Based on these formulae, we t...

Glucopyranosylidene-spiro-1,4,2-oxathiazoles were prepared in high yields by NBS-mediated spiro-cyclization of the corresponding glucosyl-hydroximothioates. In an effort to synthesize analogous glucopyranosylidene-spiro-1,2,4-oxadiazolines, with a nitrogen atom instead of the sulphur, attempted cyclizations resulted in aromatization of the heterocycle with opening of the pyranosyl ring. Enzymat...

2-(2-Alkoxycarbonyl-1-arylamino-1-propenyl)benzimidazolium and 5-(2-alkoxycarbonyl-1-arylamino-1-propenyl)triazolium salts were synthesized in good yields from the reaction of benzimidazole and triazole carbenes with ketenimines. Upon treatment with a base, both salts were converted into novel 1,3-dipoles which underwent [3+2] cycloaddition reactions with electron-deficient alkynes and allenes ...

Irradiation of &methyl spiro [2.5] oct-7-en-4-one through its singlet excited state resulted in the formation of 4-methyl spirO [2.5] oct-4-en -6-one. We have used the cyclopropyl moiety in the molecule as a probe to study the operating mechanism in the photochemistry of ?, ?-unsaturated compounds. The results showed that this photoisomerization probably occurs through a concerted process.

Hole transporting materials (HTMs) play essential roles in facilitating hole extraction and suppressing recombination lead halide perovskite solar cells (PSCs). High levels of p-doping HTMs is necessary for achieving high device performance, attributed to an increased electrical conductivity. In this work, we provide evidences that the poor performance PSCs with low doping (i.e., 4 mol% spiro-O...

Electrophilic ring opening of spiro-cyclopropanecarboxylated sugars followed by reaction with DBU revealed interesting ring-contraction and ring-expansion reactions depending on the substrate and the kind of hydroxyl protective group present adjacent to the spiro center. A stereoselective method for accessing a new class of carbon chain extended keto-furanoses and C-glycosylated bicyclic compou...

Chiral spiro phosphorus ligands including monophosphoramidites and diphosphines, which contained 1,1'-spirobiindane as a backbone, were designed and synthesized. These spiro ligands were proven to be highly efficient for rhodiumand ruthenium-catalyzed asymmetric hydrogenations of prochiral olefins and ketones with excellent enantioselectivities.

Sulfonic acid functionalized SBA-15 (SBA-Pr-SO3H) with pore size 6 nm as an efficient heterogeneous nanoporous solid acid catalyst exhibited good catalytic activity in the Biginelli-like reaction in the synthesis of spiroheterobicyclic rings with good yield and good recyclability. Spiro-pyrimidinethiones/spiro-pyrimidinones-barbituric acid derivatives were synthesized in a simple and efficient ...

In an effort to develop new and possibly better types of barbiturates, suitable for intravenous use, a large number of spiro-barbiturates have been prepared by a ring closure on the 5-carbon atom of the barbituric acid and afforded for pharmacologic study. Spiro(2'-ethyl-3',5'-dimethyl cyclopentane) thio-barbituric acid appears to be the most promising product of a series of 50 analogues. Stoel...

In high performance perovskite based solar cells, CH3NH3PbI3 is the key material. We carried out a study on charge diffusion in spin-coated CH3NH3PbI3 perovskite thin film by transient fluorescent spectroscopy. A thickness-dependent fluorescent lifetime was found. By coating the film with an electron or hole transfer layer, [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) or 2,2',7,7'-tetrakis...