Density functional theory calculations predict that strongly π-electron donating functionalities such as ylidic groups can be used as an ideal structural motif for stabilizing the hitherto unknown neutral fivemembere...Density functional theory calculations predict that strongly π-electron donating functionalities such as ylidic groups can be used as an ideal structural motif for stabilizing the hitherto unknown neutral fivemembered boron(I)carbenoids.The boron(Ⅰ)carbenoids proposed in this study possess the highest singlet-triplet energy separation values(ΔE_(S-T)=25.5-42.3 kcal mol^(-1))known to date and are strongly nucleophilic in nature.In addition,the majority of these borylenes are found to be capable of activating a variety of enthalpically strong bonds such as C-H and C-F bonds,whose computed relatively lower energy barriers than experimentally evaluated systems such as cAAC confirm their potential in small molecule activation.In addition,the combined activation strain model-energy decomposition analysis(ASM-EDA)methodology was applied to quantitatively rationalize the different reactivity trends exhibited by the proposed borylenes.展开更多
Carboranes are a class of polyhedral boron-carbon molecular clusters,they can serve as versatile ligands in stabilizing low-valent main group element compounds,due to their exceptionally thermal and chemical stabiliti...Carboranes are a class of polyhedral boron-carbon molecular clusters,they can serve as versatile ligands in stabilizing low-valent main group element compounds,due to their exceptionally thermal and chemical stabilities,easy modifications at the cage carbon vertices,as well as large spherical steric effects.These carborane-based ligands provide interesting opportunities for the synthesis of low-valent main group element compounds with novel structure and reactivity,which indeed enrich the chemistry of low-valent element main group compounds.This review summarizes the recent advances in the chemistry of lowvalent group 13 and group 14 element compounds supported by carborane-based ligands.Achievements and perspectives in this new and flourishing field are discussed in this review.展开更多
Dinitrogen activation under mild conditions is important but extremely challenging due to the inert nature of the N≡N triple bond evidenced by high bond dissociation energy(945 k J/mol) and large HOMOLUMO gap(10.8 e ...Dinitrogen activation under mild conditions is important but extremely challenging due to the inert nature of the N≡N triple bond evidenced by high bond dissociation energy(945 k J/mol) and large HOMOLUMO gap(10.8 e V). In comparison with largely developed transition metal systems, the reported main group species on dinitrogen activation are rare. Here, we carry out density functional theory calculations on methyleneboranes to understand the reaction mechanisms of their dinitrogen activation. It is found that the methyleneboranes without any substituent at the boron atom performs best on dinitrogen activation, which could be contributed to its small singlet-triplet gap. In addition, strong correlations are achieved on dinitrogen activation between the singlet-triplet energy gap and the reaction energies for the formation of the end-on products as well as the side-on ones. The principal interacting orbital analysis suggests that methyleneboranes can mimic transition metals to cleave the N≡N triple bond. Our findings could be helpful for experimental chemists aiming at dinitrogen activation by main group species.展开更多
基金the Department of Science and Technology(DST-SERB),New Delhi for providing financial assistance in the form of a research project(project no.CRG/2020/004775)UGC for a NFOBC fellowship+1 种基金the Spanish MCIN/AEI/10.13039/501100011033(Grants PID2019-106184GB-I00 and RED2018-102387-T)for financial supportthe MINECO for a FPI grant.
文摘Density functional theory calculations predict that strongly π-electron donating functionalities such as ylidic groups can be used as an ideal structural motif for stabilizing the hitherto unknown neutral fivemembered boron(I)carbenoids.The boron(Ⅰ)carbenoids proposed in this study possess the highest singlet-triplet energy separation values(ΔE_(S-T)=25.5-42.3 kcal mol^(-1))known to date and are strongly nucleophilic in nature.In addition,the majority of these borylenes are found to be capable of activating a variety of enthalpically strong bonds such as C-H and C-F bonds,whose computed relatively lower energy barriers than experimentally evaluated systems such as cAAC confirm their potential in small molecule activation.In addition,the combined activation strain model-energy decomposition analysis(ASM-EDA)methodology was applied to quantitatively rationalize the different reactivity trends exhibited by the proposed borylenes.
基金the National Natural Science Foundation of China(No.21901039)the Natural Science Foundation of Jiangsu Province(No.BK20190327)。
文摘Carboranes are a class of polyhedral boron-carbon molecular clusters,they can serve as versatile ligands in stabilizing low-valent main group element compounds,due to their exceptionally thermal and chemical stabilities,easy modifications at the cage carbon vertices,as well as large spherical steric effects.These carborane-based ligands provide interesting opportunities for the synthesis of low-valent main group element compounds with novel structure and reactivity,which indeed enrich the chemistry of low-valent element main group compounds.This review summarizes the recent advances in the chemistry of lowvalent group 13 and group 14 element compounds supported by carborane-based ligands.Achievements and perspectives in this new and flourishing field are discussed in this review.
基金Financial support by the National Science Foundation of China (No. 22073079)the Top-Notch Young Talents Program of China is gratefully acknowledged。
文摘Dinitrogen activation under mild conditions is important but extremely challenging due to the inert nature of the N≡N triple bond evidenced by high bond dissociation energy(945 k J/mol) and large HOMOLUMO gap(10.8 e V). In comparison with largely developed transition metal systems, the reported main group species on dinitrogen activation are rare. Here, we carry out density functional theory calculations on methyleneboranes to understand the reaction mechanisms of their dinitrogen activation. It is found that the methyleneboranes without any substituent at the boron atom performs best on dinitrogen activation, which could be contributed to its small singlet-triplet gap. In addition, strong correlations are achieved on dinitrogen activation between the singlet-triplet energy gap and the reaction energies for the formation of the end-on products as well as the side-on ones. The principal interacting orbital analysis suggests that methyleneboranes can mimic transition metals to cleave the N≡N triple bond. Our findings could be helpful for experimental chemists aiming at dinitrogen activation by main group species.
