Laser photoelectron spectrometry of the negative ions of iron and iron carbonyls. Electron affinity determination for the series Fe(CO)n, n = 0,1,2,3,4

Engelking, P. C.; Lineberger, W. C.

doi:10.1021/ja00513a019

Cited by 165 publications

(85 citation statements)

References 4 publications

(5 reference statements)

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“…Sodium dithionite (0.1%) was added to convert myoglobin to deoxy-Mb prior to each reading. Because CO loss from [Fe(CO) 5 ] and [Mn 2 (CO) 10 ] occurs only by photodissociation, 24,25 the release of CO was induced by exposing these metal carbonyl complexes to a cold light source and allowing the gas to diffuse through a membrane before reacting with myoglobin (see Figure 1A). In contrast, CO released from [Ru(CO) 3 Cl 2 ] 2 was quantified by adding aliquots of stock solutions (10 L) of the carbonyl complex in DMSO directly to the myoglobin solution.…”

Section: Detection Of Co Releasementioning

confidence: 99%

“…This is consistent with the notion that these two transition metal carbonyl complexes do not release CO unless stimulated by light. 24,25 Therefore, a source of cold light was utilized to promote CO release from carbonyls by photodissociation. The schematic representation of the device used for measuring CO from [Fe(CO) 5 ] and [Mn 2 (CO) 10 ] is shown in Figure 1A.…”

Section: Characterization Of Co-releasing Molecules (Co-rms): Detectimentioning

confidence: 99%

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Carbon Monoxide-Releasing Molecules

Motterlini

Clark

Foresti

et al. 2002

Circulation Research

898

523

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Abstract-Carbon monoxide (CO) is generated in living organisms during the degradation of heme by the enzyme heme oxygenase, which exists in constitutive (HO-2 and HO-3) and inducible (HO-1) isoforms. Carbon monoxide gas is known to dilate blood vessels in a manner similar to nitric oxide and has been recently shown to possess antiinflammatory and antiapoptotic properties. We report that a series of transition metal carbonyls, termed here carbon monoxide-releasing molecules (CO-RMs), liberate CO to elicit direct biological activities. Specifically, spectrophotometric and NMR analysis revealed that dimanganese decacarbonyl and tricarbonyldichlororuthenium (II) dimer release CO in a concentration-dependent manner. Moreover, CO-RMs caused sustained vasodilation in precontracted rat aortic rings, attenuated coronary vasoconstriction in hearts ex vivo, and significantly reduced acute hypertension in vivo. These vascular effects were mimicked by induction of HO-1 after treatment of animals with hemin, which increases endogenously generated CO. Thus, we have identified a novel class of compounds that are useful as prototypes for studying the bioactivity of CO. In the long term, transition metal carbonyls could be utilized for the therapeutic delivery of CO to alleviate vascular-and immuno-related dysfunctions. A lthough it has been known for a long time that carbon monoxide (CO) is generated in the human body, 1 only in recent years have scientists begun to explore the possible biological activities of this gaseous molecule. The main endogenous source of CO is heme oxygenase, which exists in constitutive (HO-2 and HO-3) and inducible (HO-1) isoforms; heme serves as substrate for HO-1 and HO-2 in the formation of CO, free ferrous iron, and biliverdin, the latter being rapidly converted to bilirubin by biliverdin reductase. 2 There is general consensus, supported by extensive published reports, that HO-1 represents a pivotal inducible defensive system against stressful stimuli, including UVA radiation, carcinogens, ischemia-reperfusion damage, endotoxic shock, and several other conditions characterized by production of oxygen-derived free radicals. [2][3][4] As part of its physiological and cytoprotective actions, heme oxygenase-derived CO appears to play a major role as neurotransmitter, 5-7 regulator of sinusoidal tone, 8 inhibitor of platelet aggregation, 9 and suppressor of acute hypertensive responses. 10,11 In addition, exogenously applied CO has been shown to protect against lung injury in vivo, 12,13 prevent both production of proinflammatory cytokines 14 and endothelial cell apoptosis, 15 and suppress graft rejection in mouse-to-rat cardiac transplants 16 ; all these effects are simulated by transfection of the HO-1 gene. Thus, consistent findings reveal a series of important cellular functions that support a versatile and previously unidentified role for CO. It is interesting that many of the novel properties pertaining to CO have strong analogies with the well-established biological activities elicited by nitri...

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Section: Detection Of Co Releasementioning

confidence: 99%

Section: Characterization Of Co-releasing Molecules (Co-rms): Detectimentioning

confidence: 99%

Carbon Monoxide-Releasing Molecules

Motterlini

Clark

Foresti

et al. 2002

Circulation Research

898

523

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“…However, recent experiments have employed photoelectron spectroscopy to study a variety of metal carbonyl anions, providing vibrational information for the corresponding neutral ground states. [32][33][34][35][36] Infrared spectroscopy of unsaturated neutral metal carbonyls isolated in rare gas matrices have been reported, 7,[37][38][39] and infrared photodissociation measurements have been described for metal cluster carbonyl cations using free electron lasers. [40][41][42][43][44][45] In the present study, we employ new optical parametric oscillator infrared lasers to investigate the unusual carbonyl complexes of atomic gold cations.…”

Section: Introductionmentioning

confidence: 99%

IR Photodissociation Spectroscopy and Theory of Au⁺(CO)_n Complexes: Nonclassical Carbonyls in the Gas Phase

et al. 2008

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Au+(CO)n complexes are produced in the gas phase via pulsed laser vaporization, expanded in a supersonic jet, and detected with a reflectron time-of-flight mass spectrometer. Complexes up to n = 12 are observed, with mass channels corresponding to the n = 2 and n = 4 showing enhanced intensity. To investigate coordination and structure, individual complexes are mass-selected and probed with infrared photodissociation spectroscopy. Spectra in the carbonyl stretching region are measured for the n = 3−7 species, but no photodissociation is observed for n = 1, 2 due to the strong metal cation-ligand binding. The carbonyl stretch in these systems is blue-shifted 50−100 cm-1 with respect to the free CO vibration (2143 cm-1), providing evidence that these species are so-called "nonclassical" metal carbonyls. Theory at the MP2 and CCSD(T) levels provides structures for these complexes and predicted spectra to compare to the experiment. Excellent agreement is obtained between experiment and theory, establishing that the n = 3 complex is trigonal planar and the n = 4 complex is tetrahedral. Disciplines Chemistry CommentsReprinted (adapted) ReceiVed: NoVember 21, 2007; In Final Form: December 18, 2007 Au + (CO) n complexes are produced in the gas phase via pulsed laser vaporization, expanded in a supersonic jet, and detected with a reflectron time-of-flight mass spectrometer. Complexes up to n ) 12 are observed, with mass channels corresponding to the n ) 2 and n ) 4 showing enhanced intensity. To investigate coordination and structure, individual complexes are mass-selected and probed with infrared photodissociation spectroscopy. Spectra in the carbonyl stretching region are measured for the n ) 3-7 species, but no photodissociation is observed for n ) 1, 2 due to the strong metal cation-ligand binding. The carbonyl stretch in these systems is blue-shifted 50-100 cm -1 with respect to the free CO vibration (2143 cm -1 ), providing evidence that these species are so-called "nonclassical" metal carbonyls. Theory at the MP2 and CCSD(T) levels provides structures for these complexes and predicted spectra to compare to the experiment. Excellent agreement is obtained between experiment and theory, establishing that the n ) 3 complex is trigonal planar and the n ) 4 complex is tetrahedral.

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“…Recently, a flowing afterglow-triple quadrupole apparatus for collision-induced dissociation-threshold-energy measurements has been used (13) to determine stepwise Fe0CO bond energies in anions derived from Fe(CO) 5 . When these are combined with the electron affinities (14) of the various substances Fe(CO) v it is possible to estimate the molar enthalpy of formation of Fe(CO) v . The value (13) of D f H°m{Fe(CO) 3 , g} = −(233 2 32) kJ·mol −1 is of particular interest here.…”

Section: Discussionmentioning

confidence: 99%

Thermochemistry of sulfide and thiolato derivatives of iron carbonyl, and the strengths of the iron—sulfur bonds

Connor

Göbel

1995

The Journal of Chemical Thermodynamics

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Laser photoelectron spectrometry of the negative ions of iron and iron carbonyls. Electron affinity determination for the series Fe(CO)n, n = 0,1,2,3,4

Cited by 165 publications

References 4 publications

Carbon Monoxide-Releasing Molecules

Carbon Monoxide-Releasing Molecules

IR Photodissociation Spectroscopy and Theory of Au⁺(CO)_n Complexes: Nonclassical Carbonyls in the Gas Phase

Thermochemistry of sulfide and thiolato derivatives of iron carbonyl, and the strengths of the iron—sulfur bonds

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Laser photoelectron spectrometry of the negative ions of iron and iron carbonyls. Electron affinity determination for the series Fe(CO)n, n = 0,1,2,3,4

Cited by 165 publications

References 4 publications

Carbon Monoxide-Releasing Molecules

Carbon Monoxide-Releasing Molecules

IR Photodissociation Spectroscopy and Theory of Au+(CO)n Complexes: Nonclassical Carbonyls in the Gas Phase

Thermochemistry of sulfide and thiolato derivatives of iron carbonyl, and the strengths of the iron—sulfur bonds

Contact Info

Product

Resources

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IR Photodissociation Spectroscopy and Theory of Au⁺(CO)_n Complexes: Nonclassical Carbonyls in the Gas Phase