Equilibrium structures have been determined for s-trans-1,3-butadiene and ethylene after adjusting the rotational constants obtained from rotational spectroscopy by vibration-rotation constants calculated from the results of quantum chemical calculations. For butadiene, the formal C=C bond length is 1.338 A, and the formal C-C bond length is 1.454 A. For ethylene, the C=C bond length is 1.3305 ...

The cationic nickel(II) complexes [(η-C3H5)Ni(SbPh3)2][B(3,5-(CF3)2C6H3)4] (2) and [(η3C3H5)Ni(SbPh3)2][Al(OC(CF3)3)4] (3) were prepared and their polymerization activities in aqueous systems were compared with [(η-C3H5)Ni(η-BHT)][B(3,5-(CF3)2C6H3)4] (1) (BHT ) 3,5-di-tert-butyl-4-hydroxytoluene). Cispolybutadiene is formed in nonaqueous solution polymerization. The presence of water decreases ...

Platinum is ubiquitous in the production sectors of chemicals and fuels; however, its scarcity in nature and high price will limit future proliferation of platinum-catalysed reactions. One promising approach to conserve platinum involves understanding the smallest number of platinum atoms needed to catalyse a reaction, then designing catalysts with the minimal platinum ensembles. Here we design...

The nature and energetics of the low-lying singlet states of polyenes have presented significant challenges for electronic structure methods. This is particularly true for conventional implementations of time-dependent density functional theory (TDDFT), which, because of their use of the adiabatic approximation, have difficulty in describing states of ‘doubly-excited character’. We show that us...

We report the study of the isomeric selective OH-initiated oxidation of 1,3-butadiene in the presence of O2 and NO using the LP/LIF technique. The photolysis of monodeuterated 1-iodo-3-buten-2-ol provides only one of the possible OD-butadiene adducts, the minor addition channel product, simplifying the oxidation mechanism. We find, based on analysis of OD time-dependent traces that prompt rearr...

This paper presents a study of dynamic mechanical properties of Fused Deposition Modelling (FDM) rapid prototyping processed material Acrylonitrile butadiene styrene (ABS). It involves the measurement of modulus and damping properties of the material as it is deformed under periodic stress. In this study, frequency sweep is performed in DMA 2980 equipment to determine modulus, damping and visco...

To demonstrate its applicability for realistic open systems, we apply the dynamic mean field quantum dissipative theory to simulate the photo-induced excitation and nonradiative decay of an embedded butadiene molecule. The Markovian approximation is adopted to further reduce the computational time, and the resulting Markovian formulation assumes a variation of Lindblad's semigroup form, which i...

Chain exchange between block polymer micelles in highly selective solvents, such as water, is well-known to be arrested under quiescent conditions, yet this work demonstrates that simple agitation methods can induce rapid chain exchange in these solvents. Aqueous solutions containing either pure poly(butadiene-b-ethylene oxide) or pure poly(butadiene-b-ethylene oxide-d4) micelles were combined ...

Size-inconsistency effects in molecular properties for states with valence-Rydberg mixing: The low-lying pi-> pi * states of ethylene and butadiene. Ab initio results for the low-lying I B I u states of ethylene are used to discuss size-inconsistency effects on calculated molecular properties for states where valence-Rydberg mixing is important. Results for the expectation value of x 2 , x bein...

The Diels-Alder (DA) reaction provides an attractive route to increase the number of six member rings in substituted Polycyclic Aromatic Hydrocarbons (PAHs). The density functional theory (DFT) B3LYP method has been used in this work to inquire if the substitution of H over the edge of triindenetriphenylene (pristine hemifullerene 1) and pentacyclopentacorannulene (pristine hemifullerene 2), co...