Two p-electrons are left to form the second bond, a π-bond, in a double bond. The method therefore proposes a π-bond and a π-bond together forming the double bond. Figure 4 shows ethylene before (a) and after (b) the formation of the π-bond....
The molecule or a compound may have single (C-C), double (C=C), or triple (C ≡ C) covalent bonds. Compounds can also be formed by the sharing or exchange of electrons. Each type of bond requires some energy or agent to break. T...
Compared to H2-assisted activation mode, the direct dissociation of CO2 into carbonyl (*CO) with a simplified reaction route is advantageous for CO2-related synthetic processes and catalyst upgrading, while the stable C = O double bond makes it very challenging. Herein, we construct a subna...
Our previous IR studies as well as quantum chemical DFT calculations evidenced that Cu + ions in zeolites were able to activate C C double bond in alkenes by 蟺 back donation of d electrons of Cu + to 蟺 * antibonding orbitals of alkenes. It resulted in a distinct weakening of C C ...
1b)35,36,37,38,39,40; (iii) gem-difluoroalkenes represent a class of appealing synthetic intermediates with the C–C double bond being highly polarized because of the electronegativity of fluorine and also the repulsion effect stemming from its unpaired electrons41,42. Furthermore, it is ...
which comes about from the strong contributions of the Pb 6s2electrons to the valence band density of states7. As such, there has been a focus on compounds based on heavy post-transition metal cations In+, Sn2+, Sb3+, and Bi3+, which have valence ns2electrons and, unlike Pb, are full...
Aldol condensation, one of the C–C coupling reactions, is a reaction that generates a new C–C bond between aldehyde and ketone molecules. From: Renewable and Sustainable Energy Reviews, 2023 About this pageSet alert Also in subject areas: Chemical Engineering ChemistryDiscover other topics On ...
It is found that the resonance between the π electrons on the CX double bond and the nitrogen lone pair significantly stabilizes the planar conformation in HCXNH2 (X = O, NH, CH2, S, and Se). The absolute resonance energy follows the order of formamide < thioformamide < selenoformamide,...
Recently, the visible-light-driven α-C(sp3)–H bond functionalization of glycine derivatives has been successfully used for constructing the C–C bond and C–X bond, producing a variety of α-substituted glycine derivatives efficiently and selectively (Figure 1) [37,38,39,40,41,42]. The ...
or C–H bond cleavage (Scheme 1). For substrate1, the dipicolinate oxovanadium (V) catalyst, VOdipic, effects significant C–O bond cleavage in DMSO, but exclusive C–H bond activation in pyridine solvent, followed by C–C bond cleavage of the resulting ketone [11]. In contrast, a hom...