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Papers by Conor Dullaghan
ChemInform, Sep 12, 2006
Coordination of the carbocyclic ring of hydroquinones to electrophilic transition-metal fragments... more Coordination of the carbocyclic ring of hydroquinones to electrophilic transition-metal fragments such as Mn(CO) 3 + and Rh(COD) + produces stable p-bonded g 6-complexes that are activated to facile reversible deprotonation of the-OH groups. The deprotonations are accompanied by electron transfer to the transition metal, which acts as an internal oxidizing agent or electron sink. With manganese as the metal, the resulting g 5-semiquinone and g 4-quinone complexes have been used to synthesize onetwo-and three-dimensional polymeric metal-organometallic coordination networks. With rhodium as the metal, the p-quinonoid complexes have been demonstrated to play a unique role in multifunctional CC coupling catalysis and in the synthesis of new organolithium reagents. Both classes of p-quinonoid complexes appear to have significant applications in nanochemistry by providing an excellent vehicle for templating the directed self-assembly of nanoparticles into functional materials.
Organometallics, Apr 21, 1998
Chemical reduction of a series of (η 6-benzothiophene)Mn(CO) 3 + complexes (10a-c) under CO affor... more Chemical reduction of a series of (η 6-benzothiophene)Mn(CO) 3 + complexes (10a-c) under CO affords neutral dimanganese metallathiacyclic complexes (12a-c), which have a Mn(CO) 4 moiety inserted into the C(aryl)-S bond. Reduction of (η 6-benzothiophene)Ru(C 6-Me 6) 2+ in the presence of CO and (η 6-1-Me-naphthalene)Mn(CO) 3 + affords an analogous cationic bimetallic (15), which is converted to a neutral cyclohexadienyl complex (16) by hydride addition to the carbocyclic benzothiophene ring. The sulfur atom in the metallathiacyclic ring in 12 and 16 is nucleophilic and reacts with electrophiles CF 3 SO 3 Me, HBF 4 , and W(CO) 5 (THF) to afford complexes such as 6, 14, and 17. Treatment of 12 with H 2 results in hydrogenolysis of the Mn-C σ bond and formation of the bimetallic Mn 2 (CO) 8 (H)-(SCHdCHPh) (8), which contains a Mn-Mn bond and bridging hydride and thiolate ligands. Reaction of 6 and 17 with H 2 results in desulfurization of the benzothiophene and formation of a mixture of Mn(CO) 5 SR and [Mn(CO) 4 SR] 2 (R) H, Me). Crystal structures are reported for 9 (R) Me), 12b, and 16.
Angewandte Chemie International Edition in English, 1995
PURPOSE: A method for manufacturing palladium tetraamine sulfate for the application to electropl... more PURPOSE: A method for manufacturing palladium tetraamine sulfate for the application to electroplating bath as a replenishing agent is provided to compensate exhausted palladium while minimizing corrosion of the electroplating bath by distilling a palladium nitrate solution formed from palladium and an excess amount of a nitrate solution at a specified temperature and then adding palladium sulfate and ammonium hydroxide. CONSTITUTION: A palladium nitrate solution is prepared by washing a prescribed amount of metal palladium with HCl of about 40 to 60deg.C to activate the palladium and bringing the palladium into contact with an excess amount of a nitrate solution. The nitrate solution is prepared using nitric acid and the nitrate solution is used preferably in the range of about 15 to 50 g/l. The palladium nitrate solution is distilled at a low temperature of 115deg.C or lower. Thereby, an excess amount of HNO3 is removed. Thereafter, a prescribed amount of palladium sulfate and further a prescribed amount of ammonium hydroxide are added to the resulting palladium nitrate solution to form palladium tetraamine sulfate. Thereby, a replenishing agent containing palladium in an amount of about 35 to 45 wt.% and capable of maintaining the palladium content in an electroplating bath of palladium or palladium alloy to be about 5 to 19% can be obtained.
Organometallics, 1998
Current electronic voting systems are not sufficient to satisfy trustworthy elections as they do ... more Current electronic voting systems are not sufficient to satisfy trustworthy elections as they do not provide any proofs or confirming evidences of their honesty. This lack of trustworthiness is the main reason why e-voting is not widely spread even though e-voting is expected to be more efficient than the current plain paper voting. Many experts believe that the only way to assure voters that their intended votes are casted is to use paper receipts. In this paper, we propose an efficient scheme for issuing receipts to voters in e-voting using the well-known divideand-choose method. Our scheme does not require any special printers or scanners, nor frequent observations to voting machines. In addition to that, our scheme is more secure than the previous ones.
Organometallics, 1997
Coordination of Mn(CO) 3 + to the carbocyclic ring of benzothiophenes activates the C(aryl)-S bon... more Coordination of Mn(CO) 3 + to the carbocyclic ring of benzothiophenes activates the C(aryl)-S bond to reductive cleavage, affording metallathiacycle 5. When the 7-R substituent in 5 is methyl or ethyl (but not hydrogen), rapid C(vinyl)-S bond scission ensues to give isomer 6, which subsequently undergoes a metallathiacycle ring contraction to yield complex 7.
Organometallics, 2000
The cationic manganese tricarbonyl moiety is readily coordinated to an arene ring of the centropo... more The cationic manganese tricarbonyl moiety is readily coordinated to an arene ring of the centropolyindanes 10-methyltribenzotriquinacene (MTBT) and fenestrindane (FET) to afford [(MTBT)Mn(CO)3]+ (1) and [(FET)Mn(CO)3]+ (2). An X-ray structure of 1 shows that the metal is coordinated to the convex face of the MTBT ligand. Both 1 and 2 are electrophilically activated and readily undergo regioselective and stereoselective addition reactions with mild nucleophiles.
![Research paper thumbnail of Nucleophilic addition reactions of [(polyarene)Mn(CO)3]+ complexes containing naphthalene type ligands](https://attachments.academia-assets.com/88126128/thumbnails/1.jpg)
](Inorganica Chimica Acta, 1997
[(h 6-Polyarene)Mn(CO) 3 ] q complexes containing naphthalene type ligands undergo regioselective... more [(h 6-Polyarene)Mn(CO) 3 ] q complexes containing naphthalene type ligands undergo regioselective nucleophilic addition reactions with Hand C-donors to give moderate to good yields of h 5-cyclohexadienyl complexes. Products derived from hydride addition to naphthalene, phenanthrene and acenaphthene complexes have been characterized by X-ray diffraction.
Dalton Transactions, 2006
Coordination of the carbocyclic ring of hydroquinones to electrophilic transition-metal fragments... more Coordination of the carbocyclic ring of hydroquinones to electrophilic transition-metal fragments such as Mn(CO) 3 + and Rh(COD) + produces stable p-bonded g 6-complexes that are activated to facile reversible deprotonation of the-OH groups. The deprotonations are accompanied by electron transfer to the transition metal, which acts as an internal oxidizing agent or electron sink. With manganese as the metal, the resulting g 5-semiquinone and g 4-quinone complexes have been used to synthesize onetwo-and three-dimensional polymeric metal-organometallic coordination networks. With rhodium as the metal, the p-quinonoid complexes have been demonstrated to play a unique role in multifunctional CC coupling catalysis and in the synthesis of new organolithium reagents. Both classes of p-quinonoid complexes appear to have significant applications in nanochemistry by providing an excellent vehicle for templating the directed self-assembly of nanoparticles into functional materials.
![Research paper thumbnail of Synthesis and Reactivity of [(η6-Biphenylene)Mn(CO)3]+](https://attachments.academia-assets.com/88125898/thumbnails/1.jpg)
](Chemistry - A European Journal, 1997
Biphenylene readily coordinates through one of the phenyl rings to form [ (@-biphenylene)Mn(CO),]... more Biphenylene readily coordinates through one of the phenyl rings to form [ (@-biphenylene)Mn(CO),]+ (2+), the Xray structure of which is reported. The nucleophiles H-, Me-, Me,CC(O)CH;, and P(OEt), add to 2' at a bridgehead carbon to afford high yields of cyclohexadienyl complexes (3); the X-ray structure of the product of hydride addition is reported. P(OMe), adds to 2' to give 3, which then undergoes a spontaneous Arbuzov elimination to the dimethyl phos-phonate adduct. Nucleophilic additions to 2' are unusual in that they occur at a substituted (bridgehead) carbon. A kinetic and thermodynamic study of thc reaction with P(OEt), shows that the bridgchead carbons in 2' are orders of magnitude more electrophilic than are the arene carbons in unstrained [(arene)Mn-Keywords Arbuzov reactionsbiphenylene * cyclohexa&enyl complexes * man-(CO),]' systems. ganese
Chemical Communications, 1998
Coordination of Mn(CO) 3 + to a carbocyclic ring of dibenzothiophene activates a C-S bond to redu... more Coordination of Mn(CO) 3 + to a carbocyclic ring of dibenzothiophene activates a C-S bond to reductive cleavage, affording a novel tetramanganese metallathiacycle 5 that reacts with H 2 to form a dimanganese complex 9 containing bridging hydride and thiolate ligands; methylation of 5 followed by hydrogenation results in desulfurization of the dibenzothiophene and formation of [Mn(CO) 5 (SMe)].
Angewandte Chemie, 1999
ABSTRACT Stabile ungesättigte Heterocyclen wie Benzofuran lassen sich kaum durch konventionelle k... more ABSTRACT Stabile ungesättigte Heterocyclen wie Benzofuran lassen sich kaum durch konventionelle katalytische hydrierende Behandlung aus Erdöl entfernen. In einem Modellsystem jedoch aktiviert die Koordination von Mn(CO)3+ an den aromatischen Ring von Benzofuran die C-O-Bindung für eine Insertion von [Pt(PPh3)2] [Gl. (1)]. Der Insertion geht eine Koordination des Pt-Zentrums an die Furan-C=C-Bindung voraus; in Einklang damit läßt sich in das 2,3-Dihydro-Analogon von 1, dem diese Doppelbindung fehlt, die Pt-Einheit nicht inserieren.
Angewandte Chemie, 1995
Strukturen von Calonyctin A unabhangig von den experimentellen Daten ein Energieminimum im physik... more Strukturen von Calonyctin A unabhangig von den experimentellen Daten ein Energieminimum im physikalischen Kraftfeld[201. Die glycosidischen Winkel 4 und I) liegen im erwarteten Bereich["], und die starkere Flexibilitat im Bereich von Chinovose a spiegelt sich in einer erhohten Schwankung urn ihren Mittelwert wider (Tabelle 4). Tabelle 4. Mittlere glycosidische Winkel 4 und $ ["I aus der MD-Simulation uber 75 ps bei 300 K. In der zweiten Spalte 1st die mittlere Standardabweichung D [D (x) = (x2-I ') ''' ] angegeben. 4(H'-C'-O*-C") D (4) (C′−OA−Cx−Hx)D((C'-OA-Cx-Hx) D ((C′−OA−Cx−Hx)D() Qui (a) 45.6 Qui (b) 33.0 Rha (c) 43.4 Qui (d)
Angewandte Chemie, 1996
Solbildung erhitzt. Dieses wurde anschliefjend in zwei Schritten zersetzt; zunachst wurde 5 h auf... more Solbildung erhitzt. Dieses wurde anschliefjend in zwei Schritten zersetzt; zunachst wurde 5 h auf 200°C erhitzt, danach 5 h auf 500°C; zum AbschluB wurde an Luft 10 h bei 850°C calciniert. Bei der Imprlgnierung wurden Nickelnitrat, Zitronenslure und Ethylenglycol zu einer wiBrigen Suspension des Perowskits Ca,,Sr, TiO, gegeben, der zuvor nach der Citratmethode hergestellt worden war. Die Suspension wurde zur Trockne eingedampft und bei 850°C an Luft 5 h calciniert. Beim Mischungsverfahren wurde eine Mischung van Metalloxiden gemahlen und bei 850 "C
Angewandte Chemie International Edition in English, 1996
... J. C. Huff-man. J. An7. ... 23. 1107-1117. Model Compounds for the Homogeneous Hydrodesulfuri... more ... J. C. Huff-man. J. An7. ... 23. 1107-1117. Model Compounds for the Homogeneous Hydrodesulfurization of Benzothiophene : Inser-tion of Manganese into the SC(ary1) Bond** Conor A. Dullaghan, Shouheng Sun, Gene B. Carpenter, Brandon Weldon, and Dwight A. ...
ChemInform, Sep 12, 2006
Coordination of the carbocyclic ring of hydroquinones to electrophilic transition-metal fragments... more Coordination of the carbocyclic ring of hydroquinones to electrophilic transition-metal fragments such as Mn(CO) 3 + and Rh(COD) + produces stable p-bonded g 6-complexes that are activated to facile reversible deprotonation of the-OH groups. The deprotonations are accompanied by electron transfer to the transition metal, which acts as an internal oxidizing agent or electron sink. With manganese as the metal, the resulting g 5-semiquinone and g 4-quinone complexes have been used to synthesize onetwo-and three-dimensional polymeric metal-organometallic coordination networks. With rhodium as the metal, the p-quinonoid complexes have been demonstrated to play a unique role in multifunctional CC coupling catalysis and in the synthesis of new organolithium reagents. Both classes of p-quinonoid complexes appear to have significant applications in nanochemistry by providing an excellent vehicle for templating the directed self-assembly of nanoparticles into functional materials.
Organometallics, Apr 21, 1998
Chemical reduction of a series of (η 6-benzothiophene)Mn(CO) 3 + complexes (10a-c) under CO affor... more Chemical reduction of a series of (η 6-benzothiophene)Mn(CO) 3 + complexes (10a-c) under CO affords neutral dimanganese metallathiacyclic complexes (12a-c), which have a Mn(CO) 4 moiety inserted into the C(aryl)-S bond. Reduction of (η 6-benzothiophene)Ru(C 6-Me 6) 2+ in the presence of CO and (η 6-1-Me-naphthalene)Mn(CO) 3 + affords an analogous cationic bimetallic (15), which is converted to a neutral cyclohexadienyl complex (16) by hydride addition to the carbocyclic benzothiophene ring. The sulfur atom in the metallathiacyclic ring in 12 and 16 is nucleophilic and reacts with electrophiles CF 3 SO 3 Me, HBF 4 , and W(CO) 5 (THF) to afford complexes such as 6, 14, and 17. Treatment of 12 with H 2 results in hydrogenolysis of the Mn-C σ bond and formation of the bimetallic Mn 2 (CO) 8 (H)-(SCHdCHPh) (8), which contains a Mn-Mn bond and bridging hydride and thiolate ligands. Reaction of 6 and 17 with H 2 results in desulfurization of the benzothiophene and formation of a mixture of Mn(CO) 5 SR and [Mn(CO) 4 SR] 2 (R) H, Me). Crystal structures are reported for 9 (R) Me), 12b, and 16.
Angewandte Chemie International Edition in English, 1995
PURPOSE: A method for manufacturing palladium tetraamine sulfate for the application to electropl... more PURPOSE: A method for manufacturing palladium tetraamine sulfate for the application to electroplating bath as a replenishing agent is provided to compensate exhausted palladium while minimizing corrosion of the electroplating bath by distilling a palladium nitrate solution formed from palladium and an excess amount of a nitrate solution at a specified temperature and then adding palladium sulfate and ammonium hydroxide. CONSTITUTION: A palladium nitrate solution is prepared by washing a prescribed amount of metal palladium with HCl of about 40 to 60deg.C to activate the palladium and bringing the palladium into contact with an excess amount of a nitrate solution. The nitrate solution is prepared using nitric acid and the nitrate solution is used preferably in the range of about 15 to 50 g/l. The palladium nitrate solution is distilled at a low temperature of 115deg.C or lower. Thereby, an excess amount of HNO3 is removed. Thereafter, a prescribed amount of palladium sulfate and further a prescribed amount of ammonium hydroxide are added to the resulting palladium nitrate solution to form palladium tetraamine sulfate. Thereby, a replenishing agent containing palladium in an amount of about 35 to 45 wt.% and capable of maintaining the palladium content in an electroplating bath of palladium or palladium alloy to be about 5 to 19% can be obtained.
Organometallics, 1998
Current electronic voting systems are not sufficient to satisfy trustworthy elections as they do ... more Current electronic voting systems are not sufficient to satisfy trustworthy elections as they do not provide any proofs or confirming evidences of their honesty. This lack of trustworthiness is the main reason why e-voting is not widely spread even though e-voting is expected to be more efficient than the current plain paper voting. Many experts believe that the only way to assure voters that their intended votes are casted is to use paper receipts. In this paper, we propose an efficient scheme for issuing receipts to voters in e-voting using the well-known divideand-choose method. Our scheme does not require any special printers or scanners, nor frequent observations to voting machines. In addition to that, our scheme is more secure than the previous ones.
Organometallics, 1997
Coordination of Mn(CO) 3 + to the carbocyclic ring of benzothiophenes activates the C(aryl)-S bon... more Coordination of Mn(CO) 3 + to the carbocyclic ring of benzothiophenes activates the C(aryl)-S bond to reductive cleavage, affording metallathiacycle 5. When the 7-R substituent in 5 is methyl or ethyl (but not hydrogen), rapid C(vinyl)-S bond scission ensues to give isomer 6, which subsequently undergoes a metallathiacycle ring contraction to yield complex 7.
Organometallics, 2000
The cationic manganese tricarbonyl moiety is readily coordinated to an arene ring of the centropo... more The cationic manganese tricarbonyl moiety is readily coordinated to an arene ring of the centropolyindanes 10-methyltribenzotriquinacene (MTBT) and fenestrindane (FET) to afford [(MTBT)Mn(CO)3]+ (1) and [(FET)Mn(CO)3]+ (2). An X-ray structure of 1 shows that the metal is coordinated to the convex face of the MTBT ligand. Both 1 and 2 are electrophilically activated and readily undergo regioselective and stereoselective addition reactions with mild nucleophiles.
Inorganica Chimica Acta, 1997
[(h 6-Polyarene)Mn(CO) 3 ] q complexes containing naphthalene type ligands undergo regioselective... more [(h 6-Polyarene)Mn(CO) 3 ] q complexes containing naphthalene type ligands undergo regioselective nucleophilic addition reactions with Hand C-donors to give moderate to good yields of h 5-cyclohexadienyl complexes. Products derived from hydride addition to naphthalene, phenanthrene and acenaphthene complexes have been characterized by X-ray diffraction.
Dalton Transactions, 2006
Coordination of the carbocyclic ring of hydroquinones to electrophilic transition-metal fragments... more Coordination of the carbocyclic ring of hydroquinones to electrophilic transition-metal fragments such as Mn(CO) 3 + and Rh(COD) + produces stable p-bonded g 6-complexes that are activated to facile reversible deprotonation of the-OH groups. The deprotonations are accompanied by electron transfer to the transition metal, which acts as an internal oxidizing agent or electron sink. With manganese as the metal, the resulting g 5-semiquinone and g 4-quinone complexes have been used to synthesize onetwo-and three-dimensional polymeric metal-organometallic coordination networks. With rhodium as the metal, the p-quinonoid complexes have been demonstrated to play a unique role in multifunctional CC coupling catalysis and in the synthesis of new organolithium reagents. Both classes of p-quinonoid complexes appear to have significant applications in nanochemistry by providing an excellent vehicle for templating the directed self-assembly of nanoparticles into functional materials.
Chemistry - A European Journal, 1997
Biphenylene readily coordinates through one of the phenyl rings to form [ (@-biphenylene)Mn(CO),]... more Biphenylene readily coordinates through one of the phenyl rings to form [ (@-biphenylene)Mn(CO),]+ (2+), the Xray structure of which is reported. The nucleophiles H-, Me-, Me,CC(O)CH;, and P(OEt), add to 2' at a bridgehead carbon to afford high yields of cyclohexadienyl complexes (3); the X-ray structure of the product of hydride addition is reported. P(OMe), adds to 2' to give 3, which then undergoes a spontaneous Arbuzov elimination to the dimethyl phos-phonate adduct. Nucleophilic additions to 2' are unusual in that they occur at a substituted (bridgehead) carbon. A kinetic and thermodynamic study of thc reaction with P(OEt), shows that the bridgchead carbons in 2' are orders of magnitude more electrophilic than are the arene carbons in unstrained [(arene)Mn-Keywords Arbuzov reactionsbiphenylene * cyclohexa&enyl complexes * man-(CO),]' systems. ganese
Chemical Communications, 1998
Coordination of Mn(CO) 3 + to a carbocyclic ring of dibenzothiophene activates a C-S bond to redu... more Coordination of Mn(CO) 3 + to a carbocyclic ring of dibenzothiophene activates a C-S bond to reductive cleavage, affording a novel tetramanganese metallathiacycle 5 that reacts with H 2 to form a dimanganese complex 9 containing bridging hydride and thiolate ligands; methylation of 5 followed by hydrogenation results in desulfurization of the dibenzothiophene and formation of [Mn(CO) 5 (SMe)].
Angewandte Chemie, 1999
ABSTRACT Stabile ungesättigte Heterocyclen wie Benzofuran lassen sich kaum durch konventionelle k... more ABSTRACT Stabile ungesättigte Heterocyclen wie Benzofuran lassen sich kaum durch konventionelle katalytische hydrierende Behandlung aus Erdöl entfernen. In einem Modellsystem jedoch aktiviert die Koordination von Mn(CO)3+ an den aromatischen Ring von Benzofuran die C-O-Bindung für eine Insertion von [Pt(PPh3)2] [Gl. (1)]. Der Insertion geht eine Koordination des Pt-Zentrums an die Furan-C=C-Bindung voraus; in Einklang damit läßt sich in das 2,3-Dihydro-Analogon von 1, dem diese Doppelbindung fehlt, die Pt-Einheit nicht inserieren.
Angewandte Chemie, 1995
Strukturen von Calonyctin A unabhangig von den experimentellen Daten ein Energieminimum im physik... more Strukturen von Calonyctin A unabhangig von den experimentellen Daten ein Energieminimum im physikalischen Kraftfeld[201. Die glycosidischen Winkel 4 und I) liegen im erwarteten Bereich["], und die starkere Flexibilitat im Bereich von Chinovose a spiegelt sich in einer erhohten Schwankung urn ihren Mittelwert wider (Tabelle 4). Tabelle 4. Mittlere glycosidische Winkel 4 und $ ["I aus der MD-Simulation uber 75 ps bei 300 K. In der zweiten Spalte 1st die mittlere Standardabweichung D [D (x) = (x2-I ') ''' ] angegeben. 4(H'-C'-O*-C") D (4) (C′−OA−Cx−Hx)D((C'-OA-Cx-Hx) D ((C′−OA−Cx−Hx)D() Qui (a) 45.6 Qui (b) 33.0 Rha (c) 43.4 Qui (d)
Angewandte Chemie, 1996
Solbildung erhitzt. Dieses wurde anschliefjend in zwei Schritten zersetzt; zunachst wurde 5 h auf... more Solbildung erhitzt. Dieses wurde anschliefjend in zwei Schritten zersetzt; zunachst wurde 5 h auf 200°C erhitzt, danach 5 h auf 500°C; zum AbschluB wurde an Luft 10 h bei 850°C calciniert. Bei der Imprlgnierung wurden Nickelnitrat, Zitronenslure und Ethylenglycol zu einer wiBrigen Suspension des Perowskits Ca,,Sr, TiO, gegeben, der zuvor nach der Citratmethode hergestellt worden war. Die Suspension wurde zur Trockne eingedampft und bei 850°C an Luft 5 h calciniert. Beim Mischungsverfahren wurde eine Mischung van Metalloxiden gemahlen und bei 850 "C
Angewandte Chemie International Edition in English, 1996
... J. C. Huff-man. J. An7. ... 23. 1107-1117. Model Compounds for the Homogeneous Hydrodesulfuri... more ... J. C. Huff-man. J. An7. ... 23. 1107-1117. Model Compounds for the Homogeneous Hydrodesulfurization of Benzothiophene : Inser-tion of Manganese into the SC(ary1) Bond** Conor A. Dullaghan, Shouheng Sun, Gene B. Carpenter, Brandon Weldon, and Dwight A. ...