Synthesis of [MnCl<Subscript>3</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>(Hatz)]·H<Subscript>2</Subscript>O and investigation of its structure via X-ray diffraction,spectroscopic measurements and DFT calculations

The 3-amino-1,2,4-triazole (atz)-based manganese complex was prepared and characterized through single-crystal X-ray diffraction, IR, EPR, and UV–visible spectroscopy. In the crystal structure, individual complex are interconnected through N(O)–H…Cl hydrogen bonds into 1D undulating chains running parallel to the [110] direction of the unit cell. Chains further grow into 2D supramolecular layers by way of the lattice water molecules of coordination and the chloride anions (O–H…Cl). Layers pack along the b-axis of the unit cell mediated by O–H…Cl(N) and N–H…O(Cl) hydrogen bonds forming a 3D supramolecular architecture. The theoretical calculations were also performed to optimize the structure of the complexes in the gas phase to confirm the structures proposed by X-ray crystallography. In addition, IR and UV–visible spectra of complex were calculated and compared with the corresponding experimental spectra to complete the experimental structural identification. The three-dimensional Hirshfeld surface (3D-HS) and their relative two-dimensional fingerprint plots (2D-FP) reveal that the structure is dominated by H…Cl/Cl…H (50.5%), H…O/O…H (11.3%) and N…O/O…N (10.2%) contacts.     

Converse Theorems for Final-stability

This paper deals with the converse theory for some aspects offinal-stability, for which a general qualitative theory wasfirst presented by the author in 1970. The theory of final-stabilityis concerned with the behaviour of the trajectories of a systemof differential equations with respect to two arbitrary setsand a finite interval of time.     

Convergence and decay estimates for a class of second order dissipative equations involving a non-negative potential energy

We estimate the rate of decay of the difference between a solution and its limiting equilibrium for the following abstract second order problem

     

Primary photoreactions of the 3',5'-dimethoxybenzoin cage and determination of the release rate in polar media

3',5'-dimethoxybenzoin (DMB) is an important photoremovable protecting group. The primary photoreactions of DMB acetate and fluoride following photoexcitation by a subpicosecond laser flash were investigated by pump-probe spectroscopy. The primary photoproduct is identified as a preoxetane biradical intermediate that decays by different pathways depending on solvent polarity. In polar solvents (acetonitrile, water), the biradical decays by releasing acetate or fluoride with a lifetime of about 2 ns. Thus, DMB is an excellent protecting group for the investigation of fast processes such as protein folding.     

Effect of organic modifier and temperature on the resolution of betamethasone and dexamethasone using a porous graphitic carbon column: application to their identification and confirmation in human urine by LC-ESI-MS/MS

The effects of temperature, organic modifier and the type of acid on the retention factor, the resolution and peak shape of betamethasone and dexamethasone are described. The study is performed using narrow bore porous graphitic carbon (PGC) columns online with diode-array detector (DAD) and ESI MS/MS. The results show that temperature affects the retention behaviour of the two compounds and ACN yields the best separation while no effect is obtained by changing the type of organic acid. The developed method is applied for the confirmation of dexamethasone and betamethasone in human urine.     

Robust control of multiple robots handling a constrained load

Multiple-robot systems are usually confronted with uncertainties,such as uncertainties in the manipulators and load parameters,and unmodelled dynamics. In this paper, the problem of controllingmultiple manipulators handling a constrained load is addressed.A reduced-order dynamic model of the system is first derived,and several properties of this model are established. Usingthe reduced-order model, a robust control law is proposed. Thiscontroller guarantees the uniform ultimate boundedness of theposition error, the internal-force error, and the constraint-forceerror. The proposed control law requires only the bounds onthe uncertainties of the parameters. Simulation results of twoplanar robots moving a load along a horizontal plane are givento illustrate the theoretical developments.