The mechanism of a cycloaddition reaction between singlet dichloromethylene germylene and ethylene has been investigated with B3LYP/6-31G＊ method, including geometry optimization and vibrational analysis for the invo...The mechanism of a cycloaddition reaction between singlet dichloromethylene germylene and ethylene has been investigated with B3LYP/6-31G＊ method, including geometry optimization and vibrational analysis for the involved stationary points on the potential energy surface. Energies for the involved conformations were calculated by CCSD（T）//B3LYP/6-31G＊ method. On the basis of the surface energy profile obtained with CCSD（T）// B3LYP/6-31G＊ method for the cycloaddition reaction between singlet dichloromethylene germylene and ethylene, it can be predicted that the dominant reaction pathway is that an intermediate INT1 is firstly formed between the two reactants through a barrier-free exothermic reaction of 61.7 kJ/mol, and the intermediate INT1 then isomerizes to an active four-membered ring product P2.1 via a transition state TS2, an intermediate INT2 and a transition state TS2.1, in which energy barriers are 57.7 and 42.2 kJ/mol, respectively.展开更多
X2Si=Ge： （X = H, Me, F, CI, Br, Ph, Ar...） is a new species. Its cycloaddition reaction is a new area for the study of germylene chemistry. The mechanism of cycloaddition reaction between singlet state Me2Si=Ge： a...X2Si=Ge： （X = H, Me, F, CI, Br, Ph, Ar...） is a new species. Its cycloaddition reaction is a new area for the study of germylene chemistry. The mechanism of cycloaddition reaction between singlet state Me2Si=Ge： and formaldehyde has been investigated with the CCSD（T）//MP2/cc-pvtz method. From the potential energy profile, it could be predicted that the reaction has one dominant reaction pathway. The reaction rule presented is that the two reactants first form a four-membered Si-heterocyclic ring germylene through the [2＋2] cycloaddition reaction. Because of the 4p unoccupied orbital of Ge： atom in the four-membered Si-heterocyclic ring germylene and the π orbital of formaldehyde form a π→p donor-acceptor bond, the four-membered Si-heterocyclic ring germylene further combines with formaldehyde to form an intermediate. Because the Ge atom in the intermediate undergoes sp^3 hybridization after transition state, then the intermediate isomerizes to a spiro-Ge-heterocyclic ring compound involving Si via a transition state. The research result indicates the laws of cycloaddition reaction between HzSi=Ge： and formaldehyde. It has important reference value for the cycloaddition reaction between X2Si=Ge： （X = H, Me, F, CI, Br, Ph, Ar…） and asymmetric to-bonded compounds, which is significant for the synthesis of small-ring and spiro-Ge-heterocyclic compounds involving Si. The study extends research area and enriches the research content of germylene chemistry.展开更多
The mechanism of cycloaddition reaction between singlet state H2Ge=Ge： and acetaldehyde has been investigated with the MP2/6-311＋＋G＊＊ method. From the potential energy profile, it could be predicted that the reac...The mechanism of cycloaddition reaction between singlet state H2Ge=Ge： and acetaldehyde has been investigated with the MP2/6-311＋＋G＊＊ method. From the potential energy profile, it could be predicted that the reaction has two competitive dominant reaction pathways. The reaction rule presented is that the two reactants firstly form a four-membered Ge-heterocyclic ring germylene through the [2＋2] cycloaddition reaction. As the 4p unoccupied orbital of Ge： atom in the four-membered Ge-heterocyclic ring germylene and the π orbital of acetaldehyde form a π→p donor-acceptor bond, the four-membered Ge-heterocyclic ring germylene further combines with acetaldehyde to give an intermediate. Because the Ge atom in intermediate exhibits sp3 hybridization after transition state, the intermediate isomerizes to a spiro-Ge-heterocyclic ring compound via a transition state. Simultaneously, the ring strain of the four-membered Ge-heterocyclic ring germylene makes it isomerize to a twisted four-membered ring product.展开更多
The interpretation of heterometallic bonding nature is a basic work of inorganic chemistry.By means of intermetallic substitution of germylene anions with iron halide complexes CpFe(CO)_(2)I andβ-diketiminato Fe^Ⅱch...The interpretation of heterometallic bonding nature is a basic work of inorganic chemistry.By means of intermetallic substitution of germylene anions with iron halide complexes CpFe(CO)_(2)I andβ-diketiminato Fe^Ⅱchloride,the ferrogermylene complexes 3a,3b and 4a were synthesized and structurally characterized.The structural and IR characterizations show the presence of the Ge←Feπbackbonding in molecules 3a,3b and 4a.The computational works on frontier molecular orbitals and their comparison of energy states confirmed thatσdonation andπbackbonding are both weak in these molecules,despite three complexes have longer Ge-Fe bonds,whose strength decreases slightly with the degressive electron density around Fe environment in a sequence from 3a,3b to 4a.展开更多
The mechanism of the cycloaddition reaction between singlet germylene silylene （H2Ge =Si：） and acetone has been investigated with CCSD（T）/6-31G＊//MP2/6-31 G＊ method. From the potential energy profile, we could ...The mechanism of the cycloaddition reaction between singlet germylene silylene （H2Ge =Si：） and acetone has been investigated with CCSD（T）/6-31G＊//MP2/6-31 G＊ method. From the potential energy profile, we could predict that the reaction has two competitive dominant reaction channels. The present rule of this reaction is that the [2 ＋2] cycloaddition reaction of the two π-bonds in germylene silylene and acetone generates a four-membered ring silylene with Ge. Because of the unsaturated property of Si atom in the four-membered ring silylene with Ge, it could further react with acetone, resulting in the generation of a bis-heterocyclic compound with Si and Ge. Simul- taneously, the ring strain of the four-membered ring silylene with Ge makes it isomerize to a twisted four-membered ring product.展开更多
The insertion reactions of germylene into C-Cl bond of 1-chorobenzene have been explored using density functional theory. Five germylene species have been chosen for systematically studying. All the stationary points ...The insertion reactions of germylene into C-Cl bond of 1-chorobenzene have been explored using density functional theory. Five germylene species have been chosen for systematically studying. All the stationary points were determined at the B3LYP/ 6-311＋G （d, p） level of the theory. The results show that, the smaller the AEsT of germylene, the lower the barrier height, and the electropositive substituents on the germylene can increase the reaction activity and exothermicity of insertion into C-Cl bond of 1- chorobenzene.展开更多
The mechanism of the oxide extraction reaction between singlet germylene carbene and its derivatives X2Ge=C： （X=H, F, Cl, CH3） and ethylene oxide has been investigated with B3LYP/6-311G（d,p） method. The results s...The mechanism of the oxide extraction reaction between singlet germylene carbene and its derivatives X2Ge=C： （X=H, F, Cl, CH3） and ethylene oxide has been investigated with B3LYP/6-311G（d,p） method. The results show that this kind of reaction has similar mechanism, the shift of 2p lone electron pair of O in ethylene oxide to the 2p unoccupied orbital of C in X2Ge=C： gives a p→p donor-acceptor bond, thereby leading to the formation of intermediate. As the p→p donor-acceptor bond continues to strengthen, that is the C-O bond continues to shorten, the intermediate generates product （P＋C2H4） via transition state. It is the substituent electronegativity that mainly affect the extraction reactions. When the substituent electronegativity is greater, the energy barrier is lower, and the reaction rate is greater.展开更多
The aromatic character of divalent three, five and seven-membered rings C2H2M, C4H4M and C6H6M(M=C, Si, Ge, Sn and Pb) is investigated through magnetic and geometric criteria by Density Functional Theory (DFT )method ...The aromatic character of divalent three, five and seven-membered rings C2H2M, C4H4M and C6H6M(M=C, Si, Ge, Sn and Pb) is investigated through magnetic and geometric criteria by Density Functional Theory (DFT )method using 6-311++G(3df,2p) basis set of the GAUSSIAN 98 program. The result of Nucleus-independent Chemical Shifts (NICS) (0.5) calculations show an aromatic character for singlet state of C2H2M(M=C, Si, Ge, Sn and Sn) and nonaromatic character for triplet states of C2H2M(except M=Ge and Pb). NICS (0.5) calculations show nonaromatic character for the singlet state of C4H4C and antiaromatic character for C4H4M(M=Si, Ge, Sn and Pb). In contrast, NICS (0.5) calculations indicate antiaromatic character for the triplet state of C4H4C and nonaromatic character to C4H4M(M=Si, Ge, Sn and Pb). NICS (0.5) calculations show a slightly homoaromatic character for the singlet state of C6H6M and anti-aromatic character for triplet state of C6H6M.展开更多
The H2Ge=Ge：, as well as and its derivatives （X2Ge=Ge：, X=H, Me, F, C1, Br, Ph, At, ...） is a kind of new species. Its cycloaddition reactions is a new area for the study of germylene chemistry. The mechanism of t...The H2Ge=Ge：, as well as and its derivatives （X2Ge=Ge：, X=H, Me, F, C1, Br, Ph, At, ...） is a kind of new species. Its cycloaddition reactions is a new area for the study of germylene chemistry. The mechanism of the cycloaddition reaction between singlet Me2Ge=Ge： and acetaldehyde was investigated with the B3LYP/6-31G＊ method in this work. From the potential energy profile, it could be predicted that the reaction has one dominant reaction pathway. The reaction rule is that the two reactants firstly form a four-membered Ge-heterocyclic ring germylene through the [2＋2] cycloaddition reaction. Because of the 4p unoccupied orbital of Ge： atom in the four-membered Ge-heterocyclic ring germylene and the ~ orbital of acetaldehyde forming a r^--~p donor-acceptor bond, the four-membered Ge-heterocyclic ring germylene further combines with acetaldehyde to form an intermedi- ate. Because the Ge atom in intermediate happens sp3 hybridization after transition state, then, intermediate isomerizes to a spiro-Ge-heterocyclic ring compound via a transition state. The research result indicates the laws of cycloaddition reaction between Me2Ge=Ge： and ac- etaldehyde, and lays the theory foundation of the cycloaddition reaction between H2Ge=Ge： and its derivatives （X2Ge=Ge：, X=H, Me, F, C1, Br, Ph, At, ...） and asymmetric ^-bonded compounds, which are significant for the synthesis of small-ring and spiro-Ge-heterocyclic ring compounds.展开更多
Organoboryl germanium(Ⅱ)oxides were synthesized from the 1,4-addition reaction of L′Ge(L′=HC[C(CH2)N(Ar)]C(Me)N(Ar),Ar=2,6-iPr2C6H3)with selected monosubstituted arylboronic acids RB(OH)2(R=2,6-Me2C6H3,2,4,6-Me3C6H...Organoboryl germanium(Ⅱ)oxides were synthesized from the 1,4-addition reaction of L′Ge(L′=HC[C(CH2)N(Ar)]C(Me)N(Ar),Ar=2,6-iPr2C6H3)with selected monosubstituted arylboronic acids RB(OH)2(R=2,6-Me2C6H3,2,4,6-Me3C6H2,1-Naph)at the molar ratios of 1:1 and 2:1.The mononuclear products RB(OH)OGeL(L=CH[C(Me)N(Ar)]2,Ar=2,6-iPr2C6H3;R=2,6-Me2C6H3(1),2,4,6-Me3C6H2(2),1-Naph(3))containing the Ge–O–B core were obtained smoothly through the 1:1 reaction.However,the reaction of L′Ge with 2,6-Me2C6H3B(OH)2 in a 2:1 ratio gave only the mononuclear product(1)instead of the expected binuclear one.What’s more,a new borate compound[(2,6-Me2C6H3)4B5O6]-[H:C]+(4)(:C=C[N(iPr)C(Me)]2)was concomitantly formed when the in situ prepared L′Ge was used as the precursor.In contrast,the use of 2,4,6-Me3C6H2B(OH)2 or 1-NaphB(OH)2 as the organoboryl source in the similar reaction led to the formation and isolation of the binuclear products RB(OGeL)2(R=2,4,6-Me3C6H2(5),1-Naph(6))containing the Ge–O–B–O–Ge core in a straight way.Compounds 1~6 were determined by single-crystal X-ray diffraction analysis.展开更多
The mechanism of the cycloaddition reaction of forming germanic bis-heterocyclic compound between singlet dichloro-germylene carbene and formaldehyde has been investigated with CCSD（T）//MP2/6-31G^＊ method, from the...The mechanism of the cycloaddition reaction of forming germanic bis-heterocyclic compound between singlet dichloro-germylene carbene and formaldehyde has been investigated with CCSD（T）//MP2/6-31G^＊ method, from the potential energy profile, we predict that the reaction has two competitive dominant reaction pathways. The presented rule of this reaction： the 2p unoccupied orbital of the C atom in dichloro-germylene carbene insert the π orbital of formaldehyde from oxygen side, resulting in the formation of intermediate. In the intermediate and between two reactants, because of the two bonding π orbital in dichloro-germylene carbene and formaldehyde have occurred [2＋2] cycloaddition reaction, forming two four- membered ring compounds in which Ge and O are in the opposite orientation and in the syn-position, respectively. Because of the unsaturated property of C atom from carbene in the two four-membered ring compounds, they further reacts with formaldehyde, resulting in the generation of two germanic bis-heterocyclic compounds.展开更多
基金Project supported by the Natural Science Foundation of Shandong Province of China （No. Y2002B07）.
文摘The mechanism of a cycloaddition reaction between singlet dichloromethylene germylene and ethylene has been investigated with B3LYP/6-31G＊ method, including geometry optimization and vibrational analysis for the involved stationary points on the potential energy surface. Energies for the involved conformations were calculated by CCSD（T）//B3LYP/6-31G＊ method. On the basis of the surface energy profile obtained with CCSD（T）// B3LYP/6-31G＊ method for the cycloaddition reaction between singlet dichloromethylene germylene and ethylene, it can be predicted that the dominant reaction pathway is that an intermediate INT1 is firstly formed between the two reactants through a barrier-free exothermic reaction of 61.7 kJ/mol, and the intermediate INT1 then isomerizes to an active four-membered ring product P2.1 via a transition state TS2, an intermediate INT2 and a transition state TS2.1, in which energy barriers are 57.7 and 42.2 kJ/mol, respectively.
基金supported by the National Natural Science Foundation of China(No.51102114)
文摘X2Si=Ge： （X = H, Me, F, CI, Br, Ph, Ar...） is a new species. Its cycloaddition reaction is a new area for the study of germylene chemistry. The mechanism of cycloaddition reaction between singlet state Me2Si=Ge： and formaldehyde has been investigated with the CCSD（T）//MP2/cc-pvtz method. From the potential energy profile, it could be predicted that the reaction has one dominant reaction pathway. The reaction rule presented is that the two reactants first form a four-membered Si-heterocyclic ring germylene through the [2＋2] cycloaddition reaction. Because of the 4p unoccupied orbital of Ge： atom in the four-membered Si-heterocyclic ring germylene and the π orbital of formaldehyde form a π→p donor-acceptor bond, the four-membered Si-heterocyclic ring germylene further combines with formaldehyde to form an intermediate. Because the Ge atom in the intermediate undergoes sp^3 hybridization after transition state, then the intermediate isomerizes to a spiro-Ge-heterocyclic ring compound involving Si via a transition state. The research result indicates the laws of cycloaddition reaction between HzSi=Ge： and formaldehyde. It has important reference value for the cycloaddition reaction between X2Si=Ge： （X = H, Me, F, CI, Br, Ph, Ar…） and asymmetric to-bonded compounds, which is significant for the synthesis of small-ring and spiro-Ge-heterocyclic compounds involving Si. The study extends research area and enriches the research content of germylene chemistry.
基金supported by the National Natural Science Foundation of China(No.51102114)
文摘The mechanism of cycloaddition reaction between singlet state H2Ge=Ge： and acetaldehyde has been investigated with the MP2/6-311＋＋G＊＊ method. From the potential energy profile, it could be predicted that the reaction has two competitive dominant reaction pathways. The reaction rule presented is that the two reactants firstly form a four-membered Ge-heterocyclic ring germylene through the [2＋2] cycloaddition reaction. As the 4p unoccupied orbital of Ge： atom in the four-membered Ge-heterocyclic ring germylene and the π orbital of acetaldehyde form a π→p donor-acceptor bond, the four-membered Ge-heterocyclic ring germylene further combines with acetaldehyde to give an intermediate. Because the Ge atom in intermediate exhibits sp3 hybridization after transition state, the intermediate isomerizes to a spiro-Ge-heterocyclic ring compound via a transition state. Simultaneously, the ring strain of the four-membered Ge-heterocyclic ring germylene makes it isomerize to a twisted four-membered ring product.
基金supported by National Science Foundation of China(No.22273072)the Shaanxi Provincial Enterprise Joint Fund(No.2021JLM-31)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2021JM-311)。
文摘The interpretation of heterometallic bonding nature is a basic work of inorganic chemistry.By means of intermetallic substitution of germylene anions with iron halide complexes CpFe(CO)_(2)I andβ-diketiminato Fe^Ⅱchloride,the ferrogermylene complexes 3a,3b and 4a were synthesized and structurally characterized.The structural and IR characterizations show the presence of the Ge←Feπbackbonding in molecules 3a,3b and 4a.The computational works on frontier molecular orbitals and their comparison of energy states confirmed thatσdonation andπbackbonding are both weak in these molecules,despite three complexes have longer Ge-Fe bonds,whose strength decreases slightly with the degressive electron density around Fe environment in a sequence from 3a,3b to 4a.
文摘The mechanism of the cycloaddition reaction between singlet germylene silylene （H2Ge =Si：） and acetone has been investigated with CCSD（T）/6-31G＊//MP2/6-31 G＊ method. From the potential energy profile, we could predict that the reaction has two competitive dominant reaction channels. The present rule of this reaction is that the [2 ＋2] cycloaddition reaction of the two π-bonds in germylene silylene and acetone generates a four-membered ring silylene with Ge. Because of the unsaturated property of Si atom in the four-membered ring silylene with Ge, it could further react with acetone, resulting in the generation of a bis-heterocyclic compound with Si and Ge. Simul- taneously, the ring strain of the four-membered ring silylene with Ge makes it isomerize to a twisted four-membered ring product.
基金the Natural Science Foundation of Shandong Province(No.Y2006B420) for financial support for this work.
文摘The insertion reactions of germylene into C-Cl bond of 1-chorobenzene have been explored using density functional theory. Five germylene species have been chosen for systematically studying. All the stationary points were determined at the B3LYP/ 6-311＋G （d, p） level of the theory. The results show that, the smaller the AEsT of germylene, the lower the barrier height, and the electropositive substituents on the germylene can increase the reaction activity and exothermicity of insertion into C-Cl bond of 1- chorobenzene.
文摘The mechanism of the oxide extraction reaction between singlet germylene carbene and its derivatives X2Ge=C： （X=H, F, Cl, CH3） and ethylene oxide has been investigated with B3LYP/6-311G（d,p） method. The results show that this kind of reaction has similar mechanism, the shift of 2p lone electron pair of O in ethylene oxide to the 2p unoccupied orbital of C in X2Ge=C： gives a p→p donor-acceptor bond, thereby leading to the formation of intermediate. As the p→p donor-acceptor bond continues to strengthen, that is the C-O bond continues to shorten, the intermediate generates product （P＋C2H4） via transition state. It is the substituent electronegativity that mainly affect the extraction reactions. When the substituent electronegativity is greater, the energy barrier is lower, and the reaction rate is greater.
基金Payame Noor University, Zanjan Branch foundations(伊朗)资助项目
文摘The aromatic character of divalent three, five and seven-membered rings C2H2M, C4H4M and C6H6M(M=C, Si, Ge, Sn and Pb) is investigated through magnetic and geometric criteria by Density Functional Theory (DFT )method using 6-311++G(3df,2p) basis set of the GAUSSIAN 98 program. The result of Nucleus-independent Chemical Shifts (NICS) (0.5) calculations show an aromatic character for singlet state of C2H2M(M=C, Si, Ge, Sn and Sn) and nonaromatic character for triplet states of C2H2M(except M=Ge and Pb). NICS (0.5) calculations show nonaromatic character for the singlet state of C4H4C and antiaromatic character for C4H4M(M=Si, Ge, Sn and Pb). In contrast, NICS (0.5) calculations indicate antiaromatic character for the triplet state of C4H4C and nonaromatic character to C4H4M(M=Si, Ge, Sn and Pb). NICS (0.5) calculations show a slightly homoaromatic character for the singlet state of C6H6M and anti-aromatic character for triplet state of C6H6M.
文摘The H2Ge=Ge：, as well as and its derivatives （X2Ge=Ge：, X=H, Me, F, C1, Br, Ph, At, ...） is a kind of new species. Its cycloaddition reactions is a new area for the study of germylene chemistry. The mechanism of the cycloaddition reaction between singlet Me2Ge=Ge： and acetaldehyde was investigated with the B3LYP/6-31G＊ method in this work. From the potential energy profile, it could be predicted that the reaction has one dominant reaction pathway. The reaction rule is that the two reactants firstly form a four-membered Ge-heterocyclic ring germylene through the [2＋2] cycloaddition reaction. Because of the 4p unoccupied orbital of Ge： atom in the four-membered Ge-heterocyclic ring germylene and the ~ orbital of acetaldehyde forming a r^--~p donor-acceptor bond, the four-membered Ge-heterocyclic ring germylene further combines with acetaldehyde to form an intermedi- ate. Because the Ge atom in intermediate happens sp3 hybridization after transition state, then, intermediate isomerizes to a spiro-Ge-heterocyclic ring compound via a transition state. The research result indicates the laws of cycloaddition reaction between Me2Ge=Ge： and ac- etaldehyde, and lays the theory foundation of the cycloaddition reaction between H2Ge=Ge： and its derivatives （X2Ge=Ge：, X=H, Me, F, C1, Br, Ph, At, ...） and asymmetric ^-bonded compounds, which are significant for the synthesis of small-ring and spiro-Ge-heterocyclic ring compounds.
基金the National Natural Science Foundation of China(21771194)。
文摘Organoboryl germanium(Ⅱ)oxides were synthesized from the 1,4-addition reaction of L′Ge(L′=HC[C(CH2)N(Ar)]C(Me)N(Ar),Ar=2,6-iPr2C6H3)with selected monosubstituted arylboronic acids RB(OH)2(R=2,6-Me2C6H3,2,4,6-Me3C6H2,1-Naph)at the molar ratios of 1:1 and 2:1.The mononuclear products RB(OH)OGeL(L=CH[C(Me)N(Ar)]2,Ar=2,6-iPr2C6H3;R=2,6-Me2C6H3(1),2,4,6-Me3C6H2(2),1-Naph(3))containing the Ge–O–B core were obtained smoothly through the 1:1 reaction.However,the reaction of L′Ge with 2,6-Me2C6H3B(OH)2 in a 2:1 ratio gave only the mononuclear product(1)instead of the expected binuclear one.What’s more,a new borate compound[(2,6-Me2C6H3)4B5O6]-[H:C]+(4)(:C=C[N(iPr)C(Me)]2)was concomitantly formed when the in situ prepared L′Ge was used as the precursor.In contrast,the use of 2,4,6-Me3C6H2B(OH)2 or 1-NaphB(OH)2 as the organoboryl source in the similar reaction led to the formation and isolation of the binuclear products RB(OGeL)2(R=2,4,6-Me3C6H2(5),1-Naph(6))containing the Ge–O–B–O–Ge core in a straight way.Compounds 1~6 were determined by single-crystal X-ray diffraction analysis.
基金ACKNOWLEDGMENT This work was supported by the National Natural Science Foundation of China （No.20273066）.
文摘The mechanism of the cycloaddition reaction of forming germanic bis-heterocyclic compound between singlet dichloro-germylene carbene and formaldehyde has been investigated with CCSD（T）//MP2/6-31G^＊ method, from the potential energy profile, we predict that the reaction has two competitive dominant reaction pathways. The presented rule of this reaction： the 2p unoccupied orbital of the C atom in dichloro-germylene carbene insert the π orbital of formaldehyde from oxygen side, resulting in the formation of intermediate. In the intermediate and between two reactants, because of the two bonding π orbital in dichloro-germylene carbene and formaldehyde have occurred [2＋2] cycloaddition reaction, forming two four- membered ring compounds in which Ge and O are in the opposite orientation and in the syn-position, respectively. Because of the unsaturated property of C atom from carbene in the two four-membered ring compounds, they further reacts with formaldehyde, resulting in the generation of two germanic bis-heterocyclic compounds.
