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Vladimir V. Klochkov - One of the best experts on this subject based on the ideXlab platform.
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stereoselective pco poc rearrangement of p c cage Phosphorane in the reaction of 4 5 dimethyl 2 2 oxo 1 2 diphenyl ethoxy 1 3 2 dioxaphospholane with hexafluoroacetone
Journal of Organic Chemistry, 2016Co-Authors: V F Mironov, Mudaris N. Dimukhametov, Sergey V. Efimov, Roza M. Aminova, Farida Kh. Karataeva, Dmitry B. Krivolapov, E V Mironova, Vladimir V. KlochkovAbstract:Interaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane, bearing a carboxyl group in the γ-position with respect to the phosphorus atom and obtained from d,l-butanediol, with hexafluoroacetone (CCl4, −40 °C) leads to the simultaneous formation of regio- and stereoisomeric cage-like Phosphoranes with phosphorus–carbon and phosphorus–oxygen bonds with a high stereoselectivity (>95%), whose structure was determined by 1D and 2D NMR spectroscopy and XRD. When stored as a solution in dichloromethane for one month, the PCO-isomer rearranges into the thermodynamically more stable POC-isomer of the cage-like Phosphorane. Mild hydrolysis of the PCO/POC-isomers proceeds with a high chemoselectivity and leads to the formation of P(IV)-dioxaphospholane derivatives. Acidic hydrolysis of the POC-isomer leads to the formation of an oxirane derivative with an unexpectedly high stereoselectivity (>95%). DFT calculations (using the PBE functional) allowed us to obtain structures and energies of the ...
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Stereoselective PCO/POC-Rearrangement of P–C-Cage Phosphorane in the Reaction of 4,5-Dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane with Hexafluoroacetone
2016Co-Authors: Vladimir F. Mironov, Mudaris N. Dimukhametov, Sergey V. Efimov, Roza M. Aminova, Farida Kh. Karataeva, Dmitry B. Krivolapov, Ekaterina V. Mironova, Vladimir V. KlochkovAbstract:Interaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane, bearing a carboxyl group in the γ-position with respect to the phosphorus atom and obtained from d,l-butanediol, with hexafluoroacetone (CCl4, −40 °C) leads to the simultaneous formation of regio- and stereoisomeric cage-like Phosphoranes with phosphorus–carbon and phosphorus–oxygen bonds with a high stereoselectivity (>95%), whose structure was determined by 1D and 2D NMR spectroscopy and XRD. When stored as a solution in dichloromethane for one month, the PCO-isomer rearranges into the thermodynamically more stable POC-isomer of the cage-like Phosphorane. Mild hydrolysis of the PCO/POC-isomers proceeds with a high chemoselectivity and leads to the formation of P(IV)-dioxaphospholane derivatives. Acidic hydrolysis of the POC-isomer leads to the formation of an oxirane derivative with an unexpectedly high stereoselectivity (>95%). DFT calculations (using the PBE functional) allowed us to obtain structures and energies of the initial phospholane, reaction products (PCO/POC-isomers), and an intermediate P(V)-oxaphosphirane
V F Mironov - One of the best experts on this subject based on the ideXlab platform.
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stereoselective pco poc rearrangement of p c cage Phosphorane in the reaction of 4 5 dimethyl 2 2 oxo 1 2 diphenyl ethoxy 1 3 2 dioxaphospholane with hexafluoroacetone
Journal of Organic Chemistry, 2016Co-Authors: V F Mironov, Mudaris N. Dimukhametov, Sergey V. Efimov, Roza M. Aminova, Farida Kh. Karataeva, Dmitry B. Krivolapov, E V Mironova, Vladimir V. KlochkovAbstract:Interaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane, bearing a carboxyl group in the γ-position with respect to the phosphorus atom and obtained from d,l-butanediol, with hexafluoroacetone (CCl4, −40 °C) leads to the simultaneous formation of regio- and stereoisomeric cage-like Phosphoranes with phosphorus–carbon and phosphorus–oxygen bonds with a high stereoselectivity (>95%), whose structure was determined by 1D and 2D NMR spectroscopy and XRD. When stored as a solution in dichloromethane for one month, the PCO-isomer rearranges into the thermodynamically more stable POC-isomer of the cage-like Phosphorane. Mild hydrolysis of the PCO/POC-isomers proceeds with a high chemoselectivity and leads to the formation of P(IV)-dioxaphospholane derivatives. Acidic hydrolysis of the POC-isomer leads to the formation of an oxirane derivative with an unexpectedly high stereoselectivity (>95%). DFT calculations (using the PBE functional) allowed us to obtain structures and energies of the ...
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caged Phosphorane with p c bond based on chloral and 4 5 dimethyl 2 2 oxo 1 2 diphenylethoxy 1 3 2 dioxaphospholane
Russian Journal of General Chemistry, 2015Co-Authors: Mudaris N. Dimukhametov, Dmitry B. Krivolapov, V F Mironov, E V Mironova, G A Ivkova, L M AbdrakhmanovaAbstract:The key methods of caged Phosphoranes synthesis are analyzed. Reaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenylethoxy)-1,3,2-dioxaphospholane (prepared from the meso-form of 2,3-butanediol) with chloral has yielded the caged Phosphorane containing a phosphorus-carbon bond: 1,1-(1,2-dimethylethylenedioxy)-3,4-diphenyl-6-trichloromethyl-2,5,7,1-trioxaphosphabicyclo[2.2.11,4]heptane; spatial structure of the product has been elucidated with X-ray diffraction analysis.
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new reaction in the ternary system phenanthrenequinone phosphorus trichloride arylacetylene
Doklady Chemistry, 2002Co-Authors: V F Mironov, T A Baronova, A T Gubaidullin, R Z Musin, N M Azancheev, Sh K Latypov, Alexey B Dobrynin, F F Alekseev, I A Litvinov, A I KonovalovAbstract:It is known that the interaction of ortho -quinones with derivatives of trivalent phosphorus occurs rather readily and usually results in the formation of Phosphoranes [1]. These derivatives of pentacoordinated phosphorus atom containing dioxaphospholene cycles are used in organic synthesis [2]. Recently, we showed that the reaction of phenanthrenequinone ( I ) with phosphorus trichloride and phenylacetylene as a third component under mild conditions ( 20°e ) yields a new heterocyclic system, 1,2-oxaphosphatriphenylene ( IIa ) [3]. Its content in the reaction mixture ranges up to 40–45%. Together with the formation of the phosphoryl group and the P–C bond, carbon is substituted for one of the oxygen atoms in phenanthrenequinone and chlorine is introduced selectively into the seventh position of the 1-oxa2-phosphatriphenylene heterocycle ( II ). The product of the interaction of quinone I with phosphorus trichloride, Phosphorane III , which can be formed as an intermediate, is unstable and undergoes complex transformations in the absence of phenylacetylene.
Yongwei Zhang - One of the best experts on this subject based on the ideXlab platform.
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mechanical twinning in phosphorene
Extreme Mechanics Letters, 2018Co-Authors: V Sorkin, Y Q Cai, David J Srolovitz, Yongwei ZhangAbstract:Abstract We investigate the deformation and failure mechanisms of phosphorene sheet and nanoribbons under uniaxial tensile strain along the zigzag direction using the density functional tight-binding method. Surprisingly, twinning occurs homogeneously across the phosphorene sheet; which significantly increases its failure strain. Vacancies within the sheet lead to the heterogeneous nucleation of twins at a lower critical strain which, subsequently, propagate across the entire sheet. Twinning always occurs heterogeneously in phosphorene nanoribbons (with or without vacancies). Propagation of the twins is interrupted by fracture which initiates along the ribbon edge. The underlying twinning mechanism is bond breaking between the atoms within phosphorene puckers and simultaneous bond formation between the atoms in neighboring puckers. This unusual deformation behavior in phosphorene may be exploited in novel nano-electronic-mechanical applications.
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mechanical twinning in phosphorene
arXiv: Materials Science, 2017Co-Authors: V Sorkin, Y Q Cai, David J Srolovitz, Yongwei ZhangAbstract:We investigate the deformation and failure mechanisms of phosphorene sheet and nanoribbons under uniaxial tensile strain along the zigzag direction using the density functional tight-binding method. Surprisingly, twin-like deformation occurs homogenously across the phosphorene sheet, which significantly increases its failure strain. Vacancies within the sheet lead to the heterogeneous nucleation of twins at a lower critical strain which, subsequently, propagate across the entire sheet. Twin-like deformation always occurs heterogeneously in phosphorene nanoribbons (with or without vacancies). Propagation of the twins is interrupted by fracture which initiates along the ribbon edge. The underlying mechanism is bond breaking between the atoms within phosphorene puckers and simultaneous bond formation between the atoms in neighboring puckers. This unusual deformation behavior in phosphorene may be exploited in novel nano-electronic-mechanical applications.
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the critical role of substrate in stabilizing phosphorene nanoflake a theoretical exploration
arXiv: Materials Science, 2016Co-Authors: Junfeng Gao, Gang Zhang, Yongwei ZhangAbstract:Phosphorene, a new two-dimensional (2D) semiconductor, has received much interest due to its robust direct band gap and high charge mobility. Currently, however, phosphorene can only be produced by mechanical or liquid exfoliation, and it is still a significant challenge to directly epitaxially grow phosphorene, which greatly hinders its mass production and, thus, applications. In epitaxial growth, the stability of nanoscale cluster or flake on a substrate is crucial. Here, we perform ab initio energy optimizations and molecular dynamics simulations to explore the critical role of substrate on the stability of a representative phosphorene flake. Our calculations show that the stability of the phosphorene nanoflake is strongly dependent on the interaction strength between the nanoflake and substrate. Specifically, the strong interaction (0.75 eV/P atom) with Cu(111) substrate breaks up the phosphorene nanoflake, while the weak interaction (0.063 eV/P atom) with h-BN substrate fails to stabilize its 2D structure. Remarkably, we find that a substrate with a moderate interaction (about 0.35 eV/P atom) is able to stabilize the 2D characteristics of the nanoflake on a realistic time scale. Our findings here provide useful guidelines for searching suitable substrates for the directly epitaxial growth of phosphorene.
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the critical role of substrate in stabilizing phosphorene nanoflake a theoretical exploration
Journal of the American Chemical Society, 2016Co-Authors: Junfeng Gao, Gang Zhang, Yongwei ZhangAbstract:Phosphorene, a new two-dimensional (2D) semiconductor, has received much interest due to its robust direct band gap and high charge mobility. Currently, however, phosphorene can only be produced by mechanical or liquid exfoliation, and it is still a significant challenge to directly epitaxially grow phosphorene, which greatly hinders its mass production and, thus, applications. In epitaxial growth, the stability of nanoscale cluster or flake on a substrate is crucial. Here, we perform ab initio energy optimizations and molecular dynamics simulations to explore the critical role of substrate on the stability of a representative phosphorene flake. Our calculations show that the stability of the phosphorene nanoflake is strongly dependent on the interaction strength between the nanoflake and substrate. Specifically, the strong interaction (0.75 eV/P atom) with Cu(111) substrate breaks up the phosphorene nanoflake, while the weak interaction (0.063 eV/P atom) with h-BN substrate fails to stabilize its 2D stru...
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thermal conductivities of single and multi layer phosphorene a molecular dynamics study
Nanoscale, 2016Co-Authors: Yingyan Zhang, Jinwu Jiang, Qingxiang Pei, Ning Wei, Yongwei ZhangAbstract:As a new two-dimensional (2D) material, phosphorene has drawn growing attention owing to its novel electronic properties, such as layer-dependent direct bandgaps and high carrier mobility. Herein we investigate the in-plane and cross-plane thermal conductivities of single- and multi-layer phosphorene, focusing on geometrical (sample size, orientation and layer number) and strain (compression and tension) effects. A strong anisotropy is found in the in-plane thermal conductivity with its value along the zigzag direction being much higher than that along the armchair direction. Interestingly, the in-plane thermal conductivity of multi-layer phosphorene is insensitive to the layer number, which is in strong contrast to that of graphene where the interlayer interactions strongly influence the thermal transport. Surprisingly, tensile strain leads to an anomalous increase in the in-plane thermal conductivity of phosphorene, in particular in the armchair direction. Both the in-plane and cross-plane thermal conductivities can be modulated by external strain; however, the strain modulation along the cross-plane direction is more effective and thus more tunable than that along the in-plane direction. Our findings here are of great importance for the thermal management in phosphorene-based nanoelectronic devices and for thermoelectric applications of phosphorene.
Dmitry B. Krivolapov - One of the best experts on this subject based on the ideXlab platform.
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stereoselective pco poc rearrangement of p c cage Phosphorane in the reaction of 4 5 dimethyl 2 2 oxo 1 2 diphenyl ethoxy 1 3 2 dioxaphospholane with hexafluoroacetone
Journal of Organic Chemistry, 2016Co-Authors: V F Mironov, Mudaris N. Dimukhametov, Sergey V. Efimov, Roza M. Aminova, Farida Kh. Karataeva, Dmitry B. Krivolapov, E V Mironova, Vladimir V. KlochkovAbstract:Interaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane, bearing a carboxyl group in the γ-position with respect to the phosphorus atom and obtained from d,l-butanediol, with hexafluoroacetone (CCl4, −40 °C) leads to the simultaneous formation of regio- and stereoisomeric cage-like Phosphoranes with phosphorus–carbon and phosphorus–oxygen bonds with a high stereoselectivity (>95%), whose structure was determined by 1D and 2D NMR spectroscopy and XRD. When stored as a solution in dichloromethane for one month, the PCO-isomer rearranges into the thermodynamically more stable POC-isomer of the cage-like Phosphorane. Mild hydrolysis of the PCO/POC-isomers proceeds with a high chemoselectivity and leads to the formation of P(IV)-dioxaphospholane derivatives. Acidic hydrolysis of the POC-isomer leads to the formation of an oxirane derivative with an unexpectedly high stereoselectivity (>95%). DFT calculations (using the PBE functional) allowed us to obtain structures and energies of the ...
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Stereoselective PCO/POC-Rearrangement of P–C-Cage Phosphorane in the Reaction of 4,5-Dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane with Hexafluoroacetone
2016Co-Authors: Vladimir F. Mironov, Mudaris N. Dimukhametov, Sergey V. Efimov, Roza M. Aminova, Farida Kh. Karataeva, Dmitry B. Krivolapov, Ekaterina V. Mironova, Vladimir V. KlochkovAbstract:Interaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane, bearing a carboxyl group in the γ-position with respect to the phosphorus atom and obtained from d,l-butanediol, with hexafluoroacetone (CCl4, −40 °C) leads to the simultaneous formation of regio- and stereoisomeric cage-like Phosphoranes with phosphorus–carbon and phosphorus–oxygen bonds with a high stereoselectivity (>95%), whose structure was determined by 1D and 2D NMR spectroscopy and XRD. When stored as a solution in dichloromethane for one month, the PCO-isomer rearranges into the thermodynamically more stable POC-isomer of the cage-like Phosphorane. Mild hydrolysis of the PCO/POC-isomers proceeds with a high chemoselectivity and leads to the formation of P(IV)-dioxaphospholane derivatives. Acidic hydrolysis of the POC-isomer leads to the formation of an oxirane derivative with an unexpectedly high stereoselectivity (>95%). DFT calculations (using the PBE functional) allowed us to obtain structures and energies of the initial phospholane, reaction products (PCO/POC-isomers), and an intermediate P(V)-oxaphosphirane
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caged Phosphorane with p c bond based on chloral and 4 5 dimethyl 2 2 oxo 1 2 diphenylethoxy 1 3 2 dioxaphospholane
Russian Journal of General Chemistry, 2015Co-Authors: Mudaris N. Dimukhametov, Dmitry B. Krivolapov, V F Mironov, E V Mironova, G A Ivkova, L M AbdrakhmanovaAbstract:The key methods of caged Phosphoranes synthesis are analyzed. Reaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenylethoxy)-1,3,2-dioxaphospholane (prepared from the meso-form of 2,3-butanediol) with chloral has yielded the caged Phosphorane containing a phosphorus-carbon bond: 1,1-(1,2-dimethylethylenedioxy)-3,4-diphenyl-6-trichloromethyl-2,5,7,1-trioxaphosphabicyclo[2.2.11,4]heptane; spatial structure of the product has been elucidated with X-ray diffraction analysis.
Mudaris N. Dimukhametov - One of the best experts on this subject based on the ideXlab platform.
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stereoselective pco poc rearrangement of p c cage Phosphorane in the reaction of 4 5 dimethyl 2 2 oxo 1 2 diphenyl ethoxy 1 3 2 dioxaphospholane with hexafluoroacetone
Journal of Organic Chemistry, 2016Co-Authors: V F Mironov, Mudaris N. Dimukhametov, Sergey V. Efimov, Roza M. Aminova, Farida Kh. Karataeva, Dmitry B. Krivolapov, E V Mironova, Vladimir V. KlochkovAbstract:Interaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane, bearing a carboxyl group in the γ-position with respect to the phosphorus atom and obtained from d,l-butanediol, with hexafluoroacetone (CCl4, −40 °C) leads to the simultaneous formation of regio- and stereoisomeric cage-like Phosphoranes with phosphorus–carbon and phosphorus–oxygen bonds with a high stereoselectivity (>95%), whose structure was determined by 1D and 2D NMR spectroscopy and XRD. When stored as a solution in dichloromethane for one month, the PCO-isomer rearranges into the thermodynamically more stable POC-isomer of the cage-like Phosphorane. Mild hydrolysis of the PCO/POC-isomers proceeds with a high chemoselectivity and leads to the formation of P(IV)-dioxaphospholane derivatives. Acidic hydrolysis of the POC-isomer leads to the formation of an oxirane derivative with an unexpectedly high stereoselectivity (>95%). DFT calculations (using the PBE functional) allowed us to obtain structures and energies of the ...
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Stereoselective PCO/POC-Rearrangement of P–C-Cage Phosphorane in the Reaction of 4,5-Dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane with Hexafluoroacetone
2016Co-Authors: Vladimir F. Mironov, Mudaris N. Dimukhametov, Sergey V. Efimov, Roza M. Aminova, Farida Kh. Karataeva, Dmitry B. Krivolapov, Ekaterina V. Mironova, Vladimir V. KlochkovAbstract:Interaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane, bearing a carboxyl group in the γ-position with respect to the phosphorus atom and obtained from d,l-butanediol, with hexafluoroacetone (CCl4, −40 °C) leads to the simultaneous formation of regio- and stereoisomeric cage-like Phosphoranes with phosphorus–carbon and phosphorus–oxygen bonds with a high stereoselectivity (>95%), whose structure was determined by 1D and 2D NMR spectroscopy and XRD. When stored as a solution in dichloromethane for one month, the PCO-isomer rearranges into the thermodynamically more stable POC-isomer of the cage-like Phosphorane. Mild hydrolysis of the PCO/POC-isomers proceeds with a high chemoselectivity and leads to the formation of P(IV)-dioxaphospholane derivatives. Acidic hydrolysis of the POC-isomer leads to the formation of an oxirane derivative with an unexpectedly high stereoselectivity (>95%). DFT calculations (using the PBE functional) allowed us to obtain structures and energies of the initial phospholane, reaction products (PCO/POC-isomers), and an intermediate P(V)-oxaphosphirane
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caged Phosphorane with p c bond based on chloral and 4 5 dimethyl 2 2 oxo 1 2 diphenylethoxy 1 3 2 dioxaphospholane
Russian Journal of General Chemistry, 2015Co-Authors: Mudaris N. Dimukhametov, Dmitry B. Krivolapov, V F Mironov, E V Mironova, G A Ivkova, L M AbdrakhmanovaAbstract:The key methods of caged Phosphoranes synthesis are analyzed. Reaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenylethoxy)-1,3,2-dioxaphospholane (prepared from the meso-form of 2,3-butanediol) with chloral has yielded the caged Phosphorane containing a phosphorus-carbon bond: 1,1-(1,2-dimethylethylenedioxy)-3,4-diphenyl-6-trichloromethyl-2,5,7,1-trioxaphosphabicyclo[2.2.11,4]heptane; spatial structure of the product has been elucidated with X-ray diffraction analysis.
