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Bayesian optimization based on Gaussian process regression was applied to optimize the conditions for the highly sensitive detection of surface contamination by laser-induced breakdown spectroscopy (LIBS). Three experimental parameters for laser ablation–pulse energy, stage height, and detection height, with 2160 possible combinations were employed for simultaneous optimization. The reciprocal value of the limit of detection (LOD) was defined as a target variable. This value was obtained from ten LIBS measurements of a pair of samples: a clean substrate and a sample with adhered silicone oil with a specified surface concentration. In total, 173 experiments under 91 conditions were completed in 16 optimization rounds. Six candidate conditions for LOD evaluation were specified based on the optimization results. The LOD evaluation by LIBS employing a detection system using an intensified charge-coupled device provided the lowest LOD value of 0.084 ± 0.008 μg cm−2. [ABSTRACT FROM AUTHOR]

In the chemistry toward generating benzdiyne from five benzenetetracarboxylic dianhydride derivatives, ketene formation was exclusively observed in the photolysis of difluorobenzenetetracarboxylic dianhydride in a nitrogen matrix at 13 K. The structure of the ketenes indicates that the dominant process in the benzdyine chemistry is an unprecedented ring cleavage rather than Wolff rearrangement.

The study was done where novel dyes were developed for use in dye-sensitized nanocrystalline TiO2 solar cells (DSSCs) and spectroscopic studies. The study discusses molecular designs of coumarin dyes for efficient dye-sensitized solar cells in detail.

Research has been conducted on the benzenetetracarboxylic dianhydrides derivatives. The wavelength-selective photolysis of these derivatives carried out in nitrogen matrixes and the benzdiynes' generation and decomposition dynamics in the nitrogen matrixes have been investigated and are discussed.

Studies were conducted to investigate the generation of 1- and 2-naphthynes by the photolyses of 1,2- and 2,3-naphthalenedicarboxylic anhydrides respectively. Findings indicate that the ultraviolet-visible (UV-Vis) absorption spectra of reactive intermediates generated in the argon matrix is well described by computations based on INDO/S and time-dependent density functional theory (TD-DFT) methods.

The dynamics of ultrafast electron injection from a coumarin derivative, which is an efficient photosensitizer for dye-sensitized solar cells, into the conduction band of TiO2 nanocrystalline films are investigated by means of femtosecond transient absorption spectroscopy in a wide wavelength range from 600 nm to 10 Mum. The electron injection efficiency was found to increase by a factor of 1.37 in the presence of Li (super +) ions.

Oligothiophene-containing coumarin dyes fully functionalized are developed for dye-sensitized nanocrystalline TiO(sub 2) solar cells (DSSCs). DSSCs based on the dyes gave good performance in terms of incident photon-to-current conversion efficiency (IPCE) in the range of 400-800 nm.

The kinetic stabilities of the dehydrobenzoannulenes (DBAs) are compared with the related dehydrobenzoannulenes with respect to the topology of the pi-systems. The tropicity of the [14]DBA is discussed based on its experimental and theoretical 1HNMR chemical shifts.

The IR spectra of 3,4-benzotropone (2) and naphtho [2,3-c] tropone (3) isolated in nitrogen matrices at 13 kappas are observed. Self-consistent reaction field calculations on 3,4-benzotropone using the Onsager ipolar-sphere model indicate that the observed differences in the spectra reflect structural changes induced in the tropones by the surrounding media.

Research has been conducted on benzdiyne derivatives. The authors describe the use of density functional theory in investigating the effect of substituents on the benzdiyne derivative properties

A comprehensive laser flash photolysis study on photoinduced electron transfers both via excited fullerenes and excited ligothiphene/polythiphene in solution by selective excitation using laser light at various wavelengths is conducted. Smaller electron-transfer yields of longer oligomers indicate the contribution of other deactivation processes such as energy transfers.

A modular and high-yielding strategy for the construction of new classes of cationic and zwitterionic Rh(I) complexes is introduced. The methodology provides access to the first [k(super 2)-P,N]Rh(I) zwitterions, a unique complex that mediates the cross-coupling of C-H and SI-H fragments.

The first method for achieving Hiyama couplings of unactivated alkyl bromides and iodides is developed. The desired carbon-carbon bond formation proceeds under mild conditions with good functional-group tolerance.

Photolysis of propellane-annelated dehydrol[12] annulene led to the generation of dibenzotetrakisdehydro[12]annulene, a highly reactive, unsaturated annulene. The generation of dibenzotetrakisdehydro[12]annulene and its characterization by the UV-vis and FTIR spectra in an argon matrix at low temperature, is reported.