Carlo Corvaja - Academia.edu (original) (raw)

Papers by Carlo Corvaja

Research paper thumbnail of ENDOR study of a radical from succinic acid. Noncrossing of proton spin levels

Journal of Magnetic Resonance (1969), 1982

Research paper thumbnail of E.s.r. spectra of reduced mono- and dinitro-derivatives of phenol and benzoic acid

Transactions of the Faraday Society

Research paper thumbnail of Restricted Motion of β Protons of the HOOCsCH2sCHsCOOH Radical Trapped in Urea Crystals

Research paper thumbnail of Synthesis of Enantiomerically Pure cis‐ and trans‐4‐Amino‐1‐oxyl‐2,2,6,6‐tetramethylpiperidine‐3‐carboxylic Acid: A Spin‐Labelled, Cyclic, Chiral β‐Amino Acid, and 3D‐Structural Analysis of a Doubly Spin‐Labelled β‐Hexapeptide

European Journal of Organic Chemistry, Jul 1, 2007

Amination of 3-carboxymethyl-1-oxyl-2,2,6,6-tetramethyl-4piperidone (1) with either (R)-or (S)-α-... more Amination of 3-carboxymethyl-1-oxyl-2,2,6,6-tetramethyl-4piperidone (1) with either (R)-or (S)-α-methylbenzylamine gave corresponding enamines 2. Whereas the reduction with NaBH 3 CN/CH 3 COOH afforded predominantly a mixture of two possible cis diastereomers of 3, (1ЈR,3S,4S)/(1ЈR,3R,4R) or (1ЈS,3R,4R)/(1ЈS,3S,4S), which could be separated by crystallisation of their HCl salts, the use of NaBH 4 /(CH 3) 2-CHCOOH as the reducing agent resulted in a mixture of one trans-and one cis diastereomer of 3 (1ЈR,3S,4R)/(1ЈR,3R,4R) or (1ЈS,3R,4S)/(1ЈS,3S,4S) in varying proportions depending upon the conditions used. The stereochemistry of the four diastereomers of 3 was clearly established by X-ray diffrac-[a] ILV, UMR

Research paper thumbnail of Electron spin resonance and torsional motion of the ? protons of the HOOC?CH2?C(OH)?COOH radical

Transactions of the Faraday Society, 1967

Research paper thumbnail of A time-resolved electron spin resonance study of mobile excited triplet states in the anthracene-1,2,4,5-tetracyanobenzene crystal

Journal of the Chemical Society Faraday Transactions Ii, 1989

Research paper thumbnail of Guest Editors� Preface

Statistica Neerlandica, Mar 1, 1992

Research paper thumbnail of Epr Studies of the Excited Triplet States of C60 and C60C2H4N(CH3) Fullerene Derivatives and C70 in Toluene and Polymethylmethacrylate Glasses and as Films

Research paper thumbnail of ChemInform Abstract: ESR OF (TERT.-BUTYL PHENYL KETONE) CHROMIUM TRICARBONYL RADICAL ANION

Chemischer Informationsdienst, 1975

Research paper thumbnail of EPR Studies of Electron Spin Polarization of Triplet Exciton and its Transfer into Triplet Traps of Naphthalene-TCNQ and Naphthalene- p Chloranil Guest Complexes in the Naphthalene-TCNB Host

Molecular Crystals and Liquid Crystals, 1983

The EPR spectra of triplet excitons in single crystals of Naphthalene-TCNB (N-TCNB) charge-transf... more The EPR spectra of triplet excitons in single crystals of Naphthalene-TCNB (N-TCNB) charge-transfer (CT) complexes show optical electron spin polarization (OEP) which is accounted for by a spin selective populating process from the excited CT singlet into an excited triplet state localized on the acceptor. OEP is also observed for triplet traps in N-TCNB crystals doped with TCNQ and pChloranil.

Research paper thumbnail of Chemically Induced Dynamic Electron Polarization of C 60 Nitroxide Bisadducts and Spin Multiplicity of Their Excited States

Appl Magn Reson, 2001

A transient electron paramagnetic resonance emission is observed after flash excitation of chloro... more A transient electron paramagnetic resonance emission is observed after flash excitation of chloroplasts at room temperature. The spectrum of the emission signal is centered at g = 2.0037 and has a linewidth AHp, = 4G (4 X 10-4 tesla). Inhibitor studies and chemical oxidation indicate that the signal is associated with Photosystem I, but the spectrum and kinetics indicate that it is neither P700 nor an ironsulfur protein. The emission signal rises with the 2-gsec time response of the instrument, and decays during the actinic flash. The emission signal is produced on only the first of a pair of strong flashes separated by 100 Msec, indicating that the precursor has not been regenerated in that time. The results are discussed with reference to the two currently accepted mechanisms for chemically induced dynamic electron polarization: the radical pair and the photochemical triplet. For several reasons the photochemical triplet mechanism is the more attractive of the two. It is suggested that at room temperature the primary photochemistry of photosystem I proceeds via a triplet state of chlorophyll, an that the species giving rise to the emission signal is the primary electron acceptor of Photosystem I.

Research paper thumbnail of Linebroadening in DF-ODMR spectra of triple excitons in the anthracene-1,2,4,5-tetracyanobenzene single crystal near its structural phase transition

Research paper thumbnail of Risonanza paramagnetica elettronica di radicali ioni di composti carbonilici

Research paper thumbnail of Theoretical Study of the Variations in the fl-Protons Hyperfine Splitting Parameter of Hydrocarbon Radicals

Research paper thumbnail of Crystal Structure of the 1:1 CT Complex of Biphenylene with 1,2,4,5-Tetracyanobenzene and EPR of Photoexcited Triplet Excitions

Molecular Crystals and Liquid Crystals, 1986

Page 1. Md. Crysf. Liq. Cryst., 1986, Vol. 141, pp, 165-178 0026-8941 18611412-0165/$20.00/ 0 0 1... more Page 1. Md. Crysf. Liq. Cryst., 1986, Vol. 141, pp, 165-178 0026-8941 18611412-0165/$20.00/ 0 0 1986 Gordon and Breach Science Publishers SA Printed in the United States of America Crystal Structure of the 1:l CT Complex of Biphenylene with ...

Research paper thumbnail of Photoexcited triplets and structural properties of single crystals of the trans-stilbene-1,2,4,5-tetracyanobenzene (1:2) complex

The Journal of Physical Chemistry, 1988

Research paper thumbnail of ENDOR Study of KOOCHOCH2COOH radicals in γ-irradiated KH oxydiacetate: Hyperfine data for α-, γ-, and H-bond protons1

Journal of Magnetic Resonance, 1983

Research paper thumbnail of Electron spin resonance spectra and orientation of 3,4-bis(dicyanomethylene)cyclobutane-1,2-dione and tetracyanoquinodimethane radical anions in liquid crystals

Journal of the Chemical Society, Faraday Transactions 2, 1975

Electron Spin Resonance Spectra and Orientation of ... 3,4-Bis(dicyanomethylene)cyclobutane - 1,2... more Electron Spin Resonance Spectra and Orientation of ... 3,4-Bis(dicyanomethylene)cyclobutane - 1,2-dione and Tetracyanoquinodimethane Radical Anions in Liquid Crystals ... BY CARL0 CORVAJA*, GIUSEPPE FARNIA AND BRUNO LUNELLI? Institute of Physical Chemistry ...

Research paper thumbnail of Crystal Structure of Diphenylacetylene-Tetracyanobenzene 1:1 CT Complex and Spin Polarization of Triplet Exciton and of Trans-Stilbene Triplet Trap

Molecular Crystals and Liquid Crystals, 1984

Abstract The crystal structure of diphenylacetylene and 1, 2, 4, 5-tetracyanobenzene 1: 1 charge ... more Abstract The crystal structure of diphenylacetylene and 1, 2, 4, 5-tetracyanobenzene 1: 1 charge transfer complex has been determined at room temperature. pe crystals belong to the monoclinic system with space group C2/m, a= 9.632 (4) Å, b= 12.403 (6) A, c= 8.131 (4 ...

Research paper thumbnail of Alkali hyperfine coupling constant in biphenylene alkali metal ion pairs

Journal of the Chemical Society, Faraday Transactions 2, 1973

Research paper thumbnail of ENDOR study of a radical from succinic acid. Noncrossing of proton spin levels

Journal of Magnetic Resonance (1969), 1982

Research paper thumbnail of E.s.r. spectra of reduced mono- and dinitro-derivatives of phenol and benzoic acid

Transactions of the Faraday Society

Research paper thumbnail of Restricted Motion of β Protons of the HOOCsCH2sCHsCOOH Radical Trapped in Urea Crystals

Research paper thumbnail of Synthesis of Enantiomerically Pure cis‐ and trans‐4‐Amino‐1‐oxyl‐2,2,6,6‐tetramethylpiperidine‐3‐carboxylic Acid: A Spin‐Labelled, Cyclic, Chiral β‐Amino Acid, and 3D‐Structural Analysis of a Doubly Spin‐Labelled β‐Hexapeptide

European Journal of Organic Chemistry, Jul 1, 2007

Amination of 3-carboxymethyl-1-oxyl-2,2,6,6-tetramethyl-4piperidone (1) with either (R)-or (S)-α-... more Amination of 3-carboxymethyl-1-oxyl-2,2,6,6-tetramethyl-4piperidone (1) with either (R)-or (S)-α-methylbenzylamine gave corresponding enamines 2. Whereas the reduction with NaBH 3 CN/CH 3 COOH afforded predominantly a mixture of two possible cis diastereomers of 3, (1ЈR,3S,4S)/(1ЈR,3R,4R) or (1ЈS,3R,4R)/(1ЈS,3S,4S), which could be separated by crystallisation of their HCl salts, the use of NaBH 4 /(CH 3) 2-CHCOOH as the reducing agent resulted in a mixture of one trans-and one cis diastereomer of 3 (1ЈR,3S,4R)/(1ЈR,3R,4R) or (1ЈS,3R,4S)/(1ЈS,3S,4S) in varying proportions depending upon the conditions used. The stereochemistry of the four diastereomers of 3 was clearly established by X-ray diffrac-[a] ILV, UMR

Research paper thumbnail of Electron spin resonance and torsional motion of the ? protons of the HOOC?CH2?C(OH)?COOH radical

Transactions of the Faraday Society, 1967

Research paper thumbnail of A time-resolved electron spin resonance study of mobile excited triplet states in the anthracene-1,2,4,5-tetracyanobenzene crystal

Journal of the Chemical Society Faraday Transactions Ii, 1989

Research paper thumbnail of Guest Editors� Preface

Statistica Neerlandica, Mar 1, 1992

Research paper thumbnail of Epr Studies of the Excited Triplet States of C60 and C60C2H4N(CH3) Fullerene Derivatives and C70 in Toluene and Polymethylmethacrylate Glasses and as Films

Research paper thumbnail of ChemInform Abstract: ESR OF (TERT.-BUTYL PHENYL KETONE) CHROMIUM TRICARBONYL RADICAL ANION

Chemischer Informationsdienst, 1975

Research paper thumbnail of EPR Studies of Electron Spin Polarization of Triplet Exciton and its Transfer into Triplet Traps of Naphthalene-TCNQ and Naphthalene- p Chloranil Guest Complexes in the Naphthalene-TCNB Host

Molecular Crystals and Liquid Crystals, 1983

The EPR spectra of triplet excitons in single crystals of Naphthalene-TCNB (N-TCNB) charge-transf... more The EPR spectra of triplet excitons in single crystals of Naphthalene-TCNB (N-TCNB) charge-transfer (CT) complexes show optical electron spin polarization (OEP) which is accounted for by a spin selective populating process from the excited CT singlet into an excited triplet state localized on the acceptor. OEP is also observed for triplet traps in N-TCNB crystals doped with TCNQ and pChloranil.

Research paper thumbnail of Chemically Induced Dynamic Electron Polarization of C 60 Nitroxide Bisadducts and Spin Multiplicity of Their Excited States

Appl Magn Reson, 2001

A transient electron paramagnetic resonance emission is observed after flash excitation of chloro... more A transient electron paramagnetic resonance emission is observed after flash excitation of chloroplasts at room temperature. The spectrum of the emission signal is centered at g = 2.0037 and has a linewidth AHp, = 4G (4 X 10-4 tesla). Inhibitor studies and chemical oxidation indicate that the signal is associated with Photosystem I, but the spectrum and kinetics indicate that it is neither P700 nor an ironsulfur protein. The emission signal rises with the 2-gsec time response of the instrument, and decays during the actinic flash. The emission signal is produced on only the first of a pair of strong flashes separated by 100 Msec, indicating that the precursor has not been regenerated in that time. The results are discussed with reference to the two currently accepted mechanisms for chemically induced dynamic electron polarization: the radical pair and the photochemical triplet. For several reasons the photochemical triplet mechanism is the more attractive of the two. It is suggested that at room temperature the primary photochemistry of photosystem I proceeds via a triplet state of chlorophyll, an that the species giving rise to the emission signal is the primary electron acceptor of Photosystem I.

Research paper thumbnail of Linebroadening in DF-ODMR spectra of triple excitons in the anthracene-1,2,4,5-tetracyanobenzene single crystal near its structural phase transition

Research paper thumbnail of Risonanza paramagnetica elettronica di radicali ioni di composti carbonilici

Research paper thumbnail of Theoretical Study of the Variations in the fl-Protons Hyperfine Splitting Parameter of Hydrocarbon Radicals

Research paper thumbnail of Crystal Structure of the 1:1 CT Complex of Biphenylene with 1,2,4,5-Tetracyanobenzene and EPR of Photoexcited Triplet Excitions

Molecular Crystals and Liquid Crystals, 1986

Page 1. Md. Crysf. Liq. Cryst., 1986, Vol. 141, pp, 165-178 0026-8941 18611412-0165/$20.00/ 0 0 1... more Page 1. Md. Crysf. Liq. Cryst., 1986, Vol. 141, pp, 165-178 0026-8941 18611412-0165/$20.00/ 0 0 1986 Gordon and Breach Science Publishers SA Printed in the United States of America Crystal Structure of the 1:l CT Complex of Biphenylene with ...

Research paper thumbnail of Photoexcited triplets and structural properties of single crystals of the trans-stilbene-1,2,4,5-tetracyanobenzene (1:2) complex

The Journal of Physical Chemistry, 1988

Research paper thumbnail of ENDOR Study of KOOCHOCH2COOH radicals in γ-irradiated KH oxydiacetate: Hyperfine data for α-, γ-, and H-bond protons1

Journal of Magnetic Resonance, 1983

Research paper thumbnail of Electron spin resonance spectra and orientation of 3,4-bis(dicyanomethylene)cyclobutane-1,2-dione and tetracyanoquinodimethane radical anions in liquid crystals

Journal of the Chemical Society, Faraday Transactions 2, 1975

Electron Spin Resonance Spectra and Orientation of ... 3,4-Bis(dicyanomethylene)cyclobutane - 1,2... more Electron Spin Resonance Spectra and Orientation of ... 3,4-Bis(dicyanomethylene)cyclobutane - 1,2-dione and Tetracyanoquinodimethane Radical Anions in Liquid Crystals ... BY CARL0 CORVAJA*, GIUSEPPE FARNIA AND BRUNO LUNELLI? Institute of Physical Chemistry ...

Research paper thumbnail of Crystal Structure of Diphenylacetylene-Tetracyanobenzene 1:1 CT Complex and Spin Polarization of Triplet Exciton and of Trans-Stilbene Triplet Trap

Molecular Crystals and Liquid Crystals, 1984

Abstract The crystal structure of diphenylacetylene and 1, 2, 4, 5-tetracyanobenzene 1: 1 charge ... more Abstract The crystal structure of diphenylacetylene and 1, 2, 4, 5-tetracyanobenzene 1: 1 charge transfer complex has been determined at room temperature. pe crystals belong to the monoclinic system with space group C2/m, a= 9.632 (4) Å, b= 12.403 (6) A, c= 8.131 (4 ...

Research paper thumbnail of Alkali hyperfine coupling constant in biphenylene alkali metal ion pairs

Journal of the Chemical Society, Faraday Transactions 2, 1973