Organic molecules can absorb or emit light in UV, visible and infra-red (IR) region of solar radiation. Fifty percent of energy of solar radiation lies in the IR region of solar spectrum and extended π-conjugated molecules containing low optical band gap can absorb NIR radiations. Recently IR molecules have grabbed the attention of synthetic chemists. Although only few molecules have been reported so far such as derivative of BODIPY, naphthalimide, porphyrins, perylene, BBT etc., they have shown highest absorbing capacity towards greater than 1100 nm. These compounds have potential applications in different fields, such as for biomedical and optoelectronic applications. In this review, we present different classes of light-harvesters with harvesting range above 1000 nm. 相似文献
A unique approach to achieve site-selective C−H olefinations exclusively at the C-3- or C-8-positions in the quinoline framework has been developed by catalyst control. Distal C(3)−H functionalization is achieved by using palladium catalysis, whereas proximal C(8)−H functionalization is obtained by employing ruthenium catalysis. Switching the site selectivity within a single substrate directly indicates two diverse pathways, which are operating under the palladium- and ruthenium-catalyzed reaction conditions. 相似文献
Stereocontrolled chemical glycosylation remains a major challenge despite vast efforts reported over many decades and so far still mainly relies on trial and error. Now it is shown that the relative reactivity value (RRV) of thioglycosides is an indicator for revealing stereoselectivities according to four types of acceptors. Mechanistic studies show that the reaction is dominated by two distinct intermediates: glycosyl triflates and glycosyl halides from N‐halosuccinimide (NXS)/TfOH. The formation of glycosyl halide is highly correlated with the production of α‐glycoside. These findings enable glycosylation reactions to be foreseen by using RRVs as an α/β‐selectivity indicator and guidelines and rules to be developed for stereocontrolled glycosylation. 相似文献
In 2011, Nathanson proposed several questions on minimal complements in a group or a semigroup. The notion of minimal complements and being a minimal complement leads to the notion of co-minimal pairs which was considered in a prior work of the authors. In this article, we study which type of subsets in the integers and free abelian groups of higher rank can be a part of a co-minimal pair. We show that a majority of lacunary sequences have this property. From the conditions established, one can show that any infinite subset of any finitely generated abelian group has uncountably many subsets which is a part of a co-minimal pair. Further, the uncountable collection of sets can be chosen so that they satisfy certain algebraic properties.
Despite phenomenal clinical success, the efficacy of platinum anticancer drugs is often compromised due to inherent and acquired drug resistant phenotypes in cancers. To circumvent this issue, we designed two heterobimetallic platinum (II)-ferrocene hybrids that display multi-pronged anticancer action. In cancer cells, our best compound, 2 , platinates DNA, produces reactive oxygen species, and has nucleus, mitochondria, and endoplasmic reticulum as potential targets. The multi-modal mechanism of action of these hybrid agents lead to non-apoptotic cell death induction which enables circumventing apoptosis resistance and significant improvement in platinum cross resistance profile. Finally, in addition to describing detail mechanistic insights, we also assessed its stability in plasma and demonstrate anticancer efficacy in an in vivo A2780 xenograft model. Strikingly, compared to oxaliplatin, our compound displays better tolerability, safety profile and efficacy in vivo. 相似文献
Journal of Solid State Electrochemistry - To protect Cu from corrosion, one of the efficient approaches is to coat the Cu substrate with passivation materials. This work investigates the ability of... 相似文献
The Ramanujan Journal - Let $$W,W'\subseteq G$$ be non-empty subsets in an arbitrary group G. The set $$W'$$ is said to be a complement to W if $$W\cdot W'=G$$ and it is minimal if no... 相似文献
An analysis is performed to study the influence of local thermal non-equilibrium
(LTNE) on unsteady MHD laminar boundary layer flow of viscous, incompressible
fluid over a vertical stretching plate embedded in a sparsely packed porous
medium in the presence of heat generation/absorption. The flow in the porous medium
is governed by Brinkman-Forchheimer extended Darcy model. A uniform heat
source or sink is presented in the solid phase. By applying similarity analysis, the
governing partial differential equations are transformed into a set of time dependent
non-linear coupled ordinary differential equations and they are solved numerically by
Runge-Kutta Fehlberg method along with shooting technique. The obtained results
are displayed graphically to illustrate the influence of different physical parameters on
the velocity, temperature profile and heat transfer rate for both fluid and solid phases.
Moreover, the numerical results obtained in this study are compared with the existing
literature in the case of LTE and found that they are in good agreement. 相似文献
In this paper, a priori error estimates are derived for the mixed finite element discretization of optimal control problems governed by fourth order elliptic partial differential equations. The state and co-state are discretized by Raviart-Thomas mixed finite element spaces and the control variable is approximated by piecewise constant functions. The error estimates derived for the state variable as well as those for the control variable seem to be new. We illustrate with a numerical example to confirm our theoretical results. 相似文献