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Papers by Keith Plowman

Research paper thumbnail of ChemInform Abstract: VIBRATIONAL SPECTRA OF SOLID TRI-μ-CARBONYL(HEXACARBONYL)DIIRON(0), FE2(CO)9

Chemischer Informationsdienst, 1978

Research paper thumbnail of ChemInform Abstract: A FACILE ROUTE TO CR(CO)5(CX) (X = SULFUR, SELENIUM) COMPLEXES

Chemischer Informationsdienst, 1977

Research paper thumbnail of Proton exchange membrane fuel cell including composite membrane comprising thick fluoropolymer film having laminated on one surface thin fluoropolymer film facing cathode

Research paper thumbnail of Gas diffusion composite electrode having novel hydrophilic layer

Research paper thumbnail of Flow field assembly for electrochemical fuel cells

Research paper thumbnail of Membrane electrode assemblies for fuel cells

Research paper thumbnail of Stabilizers for preparing polymer polyols, and process for preparing polymer polyols

Research paper thumbnail of Flow Field Structures for Membrane Electrode Assemblies of Fuel Cells

Research paper thumbnail of Method of making an electrolyte-permeable, heterogeneous polymer sheet for a gas diffusion composite electrode

Research paper thumbnail of Process for preparing polymer polyols, and polymer polyol so made

Research paper thumbnail of Electrochemical cell having gas pressurized contact between laminar, gas diffusion electrode and current collector

Research paper thumbnail of 1. Synthesis of (η6-Benzene)Dicarbonyl(Selenocarbonyl)Chromium(0) and Pentacarbonyl(Selenocarbonyl)Chromium(0)

Research paper thumbnail of Composite fuel cell membranes

A bilayer or trilayer composite ion exchange membrane suitable for use in a fuel cell. The compos... more A bilayer or trilayer composite ion exchange membrane suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. The composite membrane can be composed of a sulfonic fluoropolymer in both core and surface layers.

Research paper thumbnail of Photolysis of pentacarbonyl(selenocarbonyl)chromium(0), Cr(CO)5(CSe), in an Argon matrix at 20 K

Zeitschrift f�r anorganische und allgemeine Chemie, 1978

U.V. photolysis (254 and 366 nm) of Cr(CO),(CSe) isolated in an argon matrix at cu. ?OK produces ... more U.V. photolysis (254 and 366 nm) of Cr(CO),(CSe) isolated in an argon matrix at cu. ?OK produces a mixture of two isomeric forms of Cr(CO),(CSe), Cr(CO), and molecular CO. The two Cr(CO),(CSe) isomers are assigned square pyramidal geometries (CSe group axiitl, C, , symmetry; CSe group equatorial, C, symmetry) by comparison with the results from a previous matrix isolation i.r. study of the products formed in the U.V. photolysis of the analogous thiocarbonyl complex, Cr(CO),(CS). On further irradiation of the Cr(CO),(CSe) species with visible light (2 > @%nrn), the parent Cr(CO),(CSe) molecule is regenerated. Photolyse von in einer dr Matrix bei 20 K isoliertem Cr(CO);(CSe) Inhaltsiibersicht. Durch UV-Photolyse von Cr(CO),(CSe), das in einer-Ir-?rlatrix bei etws 20 K isoliert wurde, entstehen zwei isomere Formen von Cr(CO),(CSe) und Cr(CO), sowie CO (zu weiteren Details vgl. Bbstract).

Research paper thumbnail of Synthesis of the pentacarbonyl(chalcocarbonyl)chromium(0) complexes, Cr(CO)5(CX) (X = S, Se)

Journal of Organometallic Chemistry, 1981

The arene complexes, ($-C,H,)Cr(CO),(CX) (X = S, Se), react with excess CO gas under pressure in ... more The arene complexes, ($-C,H,)Cr(CO),(CX) (X = S, Se), react with excess CO gas under pressure in tetrahydrofuran at about 60°C to produce the Cr(CO),(CX) complexes in high yield. The IR and NlMR (13C and 170) spectra of these complexes are in complete accord with the expected C,,, molecular symmetry. Like the analogous W(CO),(CS) complex, both compounds react with cyclohexylamine to give Cr(CO),(CNC,H 1 1). However, while W(CO),(CS) undergoes stereospecific CO substitution with halide ions (Y-) to form trans-[W(CO),(CS)Y]-, the two chromium chalcocarbonyl complexes apparently undergo both CO and CX substitution to afford mixtures of [Cr(CO),Y]-and tram-[Cr(CO),(CX)Y]- .

Research paper thumbnail of Variable-temperature (295—15 K) raman spectra of dodecacarbonyl-triangulo-ruthenium(O) and -osmium(O), M3(CO)12 (M = Ru, Os)

Journal of Molecular Structure, 1981

ABSTRACT Laser Raman spectra of solid dodecacarbonyl-triangulo-ruthenium(0) and -osmium(0), M3(CO... more ABSTRACT Laser Raman spectra of solid dodecacarbonyl-triangulo-ruthenium(0) and -osmium(0), M3(CO)12 (M = Ru, Os), have been recorded at 295, 200, 100 and 15 K using a surface scanning technique to avoid sample decomposition. The data indicate that neither compound undergoes a phase change throughout the temperature range investigated. Contrary to earlier measurements at room temperature only, site-symmetry and correlation effects are more widespread than hitherto suspected.

Research paper thumbnail of Vibrational spectra of solid tri-μ-carbonyl-(hexacarbonyl)di-iron(O), Fe2(CO)9

Journal of Molecular Structure, 1978

Research paper thumbnail of Reactions of metal carbonyl complexes. XII. Synthesis of 13C-labelled (η6-benzene)chromium(O) chalcocarbonyl complexes: (η6-C6H6)Cr(13CO)3 and (η6-C6H6)Cr(13CO)2(CX) (X = S, Se)

Journal of Labelled Compounds and Radiopharmaceuticals, 1980

13C-Labelled (TI-benzene) tricarbonylchromium(0) , BzCr ((Bz = q-C H) , h a s been prepared i n a... more 13C-Labelled (TI-benzene) tricarbonylchromium(0) , BzCr ((Bz = q-C H) , h a s been prepared i n about 50% y i e l d w i t h g r e a t e r than 90 atom% 13C-enrichment by a m u l t i s t e p , photochemicallyinduced exchange of t h e t h r e e carbonyl groups i n BzCr(C0) 13C0. t h i o c a r b o n y l and selenocarbonyl d e r i v a t i v e s , BzCr (CO) (CX) 1 3

Research paper thumbnail of Vibrational spectra of the pentacarbonyl(thiocarbonyl)metal(0) complexes, M(CO)5(CS) M = chromium, tungsten) and trans-pentacarbonyl(thiocarbonyl)tungsten(0) (90% carbon-13 enriched)

Inorganic Chemistry, 1976

... A. 8. Anderson, J. Mol. Spectrosc., 44, 411 (1972). I. H. Hillier, M. F. Guest, BR Higginson,... more ... A. 8. Anderson, J. Mol. Spectrosc., 44, 411 (1972). I. H. Hillier, M. F. Guest, BR Higginson, and D. R. Lloyd, Mol. Phys., 27, 215 (1974). ... IAN S. BUTLER,*2 AMELIA GARCIA-RODRIGUEZ, KEITH R. PLOWMAN, and C. FRANK SHAW 111 Received April 27, 1976 AIC60307G ...

Research paper thumbnail of Vibrational spectra and potential constants of the (.eta.6-benzene)chromium(0) chalcocarbonyl complexes, (.eta.6-C6H6)Cr(CO)2(CX) (X = oxygen, sulfur, selenium)

Inorganic Chemistry, 1982

Infrared and laser Raman spectra have been recorded at rcom temperature for the ten chromium(0) c... more Infrared and laser Raman spectra have been recorded at rcom temperature for the ten chromium(0) chalcocarbonyl complexes BzCr('2C0)2('2CX), (B z-~,) C~(" C~)~(' * C X) , BzCr(I3CO),, B z C~('~C O)~(' * C S) , B Z C~('~C O) , ('~C S~) , and BzCr-('2co)2('3cs) (Bz = T6-C6H6; x = 0, s, Se), as solids and in various organic solvents. Vibrational assignments are proposed for most of the fundamental modes on the basis of general quadratic compliance and force field calculations in which the u(CO), v(CS), and v(CSe) vibrations were corrected for anharmonicity. The variations observed on comparing the primary CX and CrC(X) potential constants of the BzCr(CO),(CX) complexes with those of the related Cr(CO),(CX) derivatives are in line with the so-called "charge buffering ability" of CS (and presumably CSe as well) originally proposed by Andrews. Also, in agreement with earlier studies on transition-metal chalcocarbonyls, the net r-acceptor/o-donor capacity of the C X ligands increases in the order C O < CS < CSe. There is no appreciable mixing between the u(C0) and v(CS) or u(CSe) modes, but there is extensive mixing between v(CX) and the corresponding v[CrC(X)] mode, particularly in the case of the selenocarbonyl complex. In fact, comparisons of the general quadratic and energy-factored force fields for the CX modes shows that energy factoring for the thio-and selenocarbonyl is an extremely poor approximation, and any conclusions based on such calculations will be grossly in error.

Research paper thumbnail of ChemInform Abstract: VIBRATIONAL SPECTRA OF SOLID TRI-μ-CARBONYL(HEXACARBONYL)DIIRON(0), FE2(CO)9

Chemischer Informationsdienst, 1978

Research paper thumbnail of ChemInform Abstract: A FACILE ROUTE TO CR(CO)5(CX) (X = SULFUR, SELENIUM) COMPLEXES

Chemischer Informationsdienst, 1977

Research paper thumbnail of Proton exchange membrane fuel cell including composite membrane comprising thick fluoropolymer film having laminated on one surface thin fluoropolymer film facing cathode

Research paper thumbnail of Gas diffusion composite electrode having novel hydrophilic layer

Research paper thumbnail of Flow field assembly for electrochemical fuel cells

Research paper thumbnail of Membrane electrode assemblies for fuel cells

Research paper thumbnail of Stabilizers for preparing polymer polyols, and process for preparing polymer polyols

Research paper thumbnail of Flow Field Structures for Membrane Electrode Assemblies of Fuel Cells

Research paper thumbnail of Method of making an electrolyte-permeable, heterogeneous polymer sheet for a gas diffusion composite electrode

Research paper thumbnail of Process for preparing polymer polyols, and polymer polyol so made

Research paper thumbnail of Electrochemical cell having gas pressurized contact between laminar, gas diffusion electrode and current collector

Research paper thumbnail of 1. Synthesis of (η6-Benzene)Dicarbonyl(Selenocarbonyl)Chromium(0) and Pentacarbonyl(Selenocarbonyl)Chromium(0)

Research paper thumbnail of Composite fuel cell membranes

A bilayer or trilayer composite ion exchange membrane suitable for use in a fuel cell. The compos... more A bilayer or trilayer composite ion exchange membrane suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. The composite membrane can be composed of a sulfonic fluoropolymer in both core and surface layers.

Research paper thumbnail of Photolysis of pentacarbonyl(selenocarbonyl)chromium(0), Cr(CO)5(CSe), in an Argon matrix at 20 K

Zeitschrift f�r anorganische und allgemeine Chemie, 1978

U.V. photolysis (254 and 366 nm) of Cr(CO),(CSe) isolated in an argon matrix at cu. ?OK produces ... more U.V. photolysis (254 and 366 nm) of Cr(CO),(CSe) isolated in an argon matrix at cu. ?OK produces a mixture of two isomeric forms of Cr(CO),(CSe), Cr(CO), and molecular CO. The two Cr(CO),(CSe) isomers are assigned square pyramidal geometries (CSe group axiitl, C, , symmetry; CSe group equatorial, C, symmetry) by comparison with the results from a previous matrix isolation i.r. study of the products formed in the U.V. photolysis of the analogous thiocarbonyl complex, Cr(CO),(CS). On further irradiation of the Cr(CO),(CSe) species with visible light (2 > @%nrn), the parent Cr(CO),(CSe) molecule is regenerated. Photolyse von in einer dr Matrix bei 20 K isoliertem Cr(CO);(CSe) Inhaltsiibersicht. Durch UV-Photolyse von Cr(CO),(CSe), das in einer-Ir-?rlatrix bei etws 20 K isoliert wurde, entstehen zwei isomere Formen von Cr(CO),(CSe) und Cr(CO), sowie CO (zu weiteren Details vgl. Bbstract).

Research paper thumbnail of Synthesis of the pentacarbonyl(chalcocarbonyl)chromium(0) complexes, Cr(CO)5(CX) (X = S, Se)

Journal of Organometallic Chemistry, 1981

The arene complexes, ($-C,H,)Cr(CO),(CX) (X = S, Se), react with excess CO gas under pressure in ... more The arene complexes, ($-C,H,)Cr(CO),(CX) (X = S, Se), react with excess CO gas under pressure in tetrahydrofuran at about 60°C to produce the Cr(CO),(CX) complexes in high yield. The IR and NlMR (13C and 170) spectra of these complexes are in complete accord with the expected C,,, molecular symmetry. Like the analogous W(CO),(CS) complex, both compounds react with cyclohexylamine to give Cr(CO),(CNC,H 1 1). However, while W(CO),(CS) undergoes stereospecific CO substitution with halide ions (Y-) to form trans-[W(CO),(CS)Y]-, the two chromium chalcocarbonyl complexes apparently undergo both CO and CX substitution to afford mixtures of [Cr(CO),Y]-and tram-[Cr(CO),(CX)Y]- .

Research paper thumbnail of Variable-temperature (295—15 K) raman spectra of dodecacarbonyl-triangulo-ruthenium(O) and -osmium(O), M3(CO)12 (M = Ru, Os)

Journal of Molecular Structure, 1981

ABSTRACT Laser Raman spectra of solid dodecacarbonyl-triangulo-ruthenium(0) and -osmium(0), M3(CO... more ABSTRACT Laser Raman spectra of solid dodecacarbonyl-triangulo-ruthenium(0) and -osmium(0), M3(CO)12 (M = Ru, Os), have been recorded at 295, 200, 100 and 15 K using a surface scanning technique to avoid sample decomposition. The data indicate that neither compound undergoes a phase change throughout the temperature range investigated. Contrary to earlier measurements at room temperature only, site-symmetry and correlation effects are more widespread than hitherto suspected.

Research paper thumbnail of Vibrational spectra of solid tri-μ-carbonyl-(hexacarbonyl)di-iron(O), Fe2(CO)9

Journal of Molecular Structure, 1978

Research paper thumbnail of Reactions of metal carbonyl complexes. XII. Synthesis of 13C-labelled (η6-benzene)chromium(O) chalcocarbonyl complexes: (η6-C6H6)Cr(13CO)3 and (η6-C6H6)Cr(13CO)2(CX) (X = S, Se)

Journal of Labelled Compounds and Radiopharmaceuticals, 1980

13C-Labelled (TI-benzene) tricarbonylchromium(0) , BzCr ((Bz = q-C H) , h a s been prepared i n a... more 13C-Labelled (TI-benzene) tricarbonylchromium(0) , BzCr ((Bz = q-C H) , h a s been prepared i n about 50% y i e l d w i t h g r e a t e r than 90 atom% 13C-enrichment by a m u l t i s t e p , photochemicallyinduced exchange of t h e t h r e e carbonyl groups i n BzCr(C0) 13C0. t h i o c a r b o n y l and selenocarbonyl d e r i v a t i v e s , BzCr (CO) (CX) 1 3

Research paper thumbnail of Vibrational spectra of the pentacarbonyl(thiocarbonyl)metal(0) complexes, M(CO)5(CS) M = chromium, tungsten) and trans-pentacarbonyl(thiocarbonyl)tungsten(0) (90% carbon-13 enriched)

Inorganic Chemistry, 1976

... A. 8. Anderson, J. Mol. Spectrosc., 44, 411 (1972). I. H. Hillier, M. F. Guest, BR Higginson,... more ... A. 8. Anderson, J. Mol. Spectrosc., 44, 411 (1972). I. H. Hillier, M. F. Guest, BR Higginson, and D. R. Lloyd, Mol. Phys., 27, 215 (1974). ... IAN S. BUTLER,*2 AMELIA GARCIA-RODRIGUEZ, KEITH R. PLOWMAN, and C. FRANK SHAW 111 Received April 27, 1976 AIC60307G ...

Research paper thumbnail of Vibrational spectra and potential constants of the (.eta.6-benzene)chromium(0) chalcocarbonyl complexes, (.eta.6-C6H6)Cr(CO)2(CX) (X = oxygen, sulfur, selenium)

Inorganic Chemistry, 1982

Infrared and laser Raman spectra have been recorded at rcom temperature for the ten chromium(0) c... more Infrared and laser Raman spectra have been recorded at rcom temperature for the ten chromium(0) chalcocarbonyl complexes BzCr('2C0)2('2CX), (B z-~,) C~(" C~)~(' * C X) , BzCr(I3CO),, B z C~('~C O)~(' * C S) , B Z C~('~C O) , ('~C S~) , and BzCr-('2co)2('3cs) (Bz = T6-C6H6; x = 0, s, Se), as solids and in various organic solvents. Vibrational assignments are proposed for most of the fundamental modes on the basis of general quadratic compliance and force field calculations in which the u(CO), v(CS), and v(CSe) vibrations were corrected for anharmonicity. The variations observed on comparing the primary CX and CrC(X) potential constants of the BzCr(CO),(CX) complexes with those of the related Cr(CO),(CX) derivatives are in line with the so-called "charge buffering ability" of CS (and presumably CSe as well) originally proposed by Andrews. Also, in agreement with earlier studies on transition-metal chalcocarbonyls, the net r-acceptor/o-donor capacity of the C X ligands increases in the order C O < CS < CSe. There is no appreciable mixing between the u(C0) and v(CS) or u(CSe) modes, but there is extensive mixing between v(CX) and the corresponding v[CrC(X)] mode, particularly in the case of the selenocarbonyl complex. In fact, comparisons of the general quadratic and energy-factored force fields for the CX modes shows that energy factoring for the thio-and selenocarbonyl is an extremely poor approximation, and any conclusions based on such calculations will be grossly in error.