Bond Cleavage Of Molecule Research Articles

Mode-dependent enhancement and intramolecular dynamics via vibrationally mediated photodissociation

Vibrationally mediated photodissociation has been shown to control bond cleavage in molecules and probe their dynamics on the ground and excited potential energy surfaces. The application of this method to two seven-atom molecules illustrates surprising vibrational energy localization in methylamine (CH3NH2), a molecule with a torsional degree of freedom and unique information regarding intramolecular vibrational energy redistribution for the C–H methyl stretches of propyne (CH3C ≡ C–H).

S–H bond cleavage in molecules of biological interest with CpFe(dppe)I

The reaction of CpFe(dppe)I (Cp, cyclopentadienyl; dppe, Ph2P(CH2)2PPh2) with biologically active RSH molecules (L-cysteine hydrochloride, dithiothereitol and 2-mercaptoethanol) in the presence of NH4PF6 and in methanol as solvent afforded the new iron(III) thiolate complexes [CpFe(dppe)SR]PF6. The blue–black paramagnetic complexes were characterized by elemental analysis and IR, EPR and UV–visible spectroscopy. The selective S–H bond cleavage in the thiols suggests a possible utilization of the organometallic iron(II) complexes as inhibitors in some cysteine proteases. The spectroscopic properties of the new complexes have been compared with those of other Fe–S models as well ­as with Fe–S proteins. Copyright © 2000 John Wiley & Sons, Ltd.

S-H bond cleavage in molecules of biological interest with CpFe(dppe)I

The reaction of CpFe(dppe)I (Cp, cyclopentadienyl; dppe, Ph2P(CH2)2PPh2) with biologically active RSH molecules (L-cysteine hydrochloride, dithiothereitol and 2-mercaptoethanol) in the presence of NH4PF6 and in methanol as solvent afforded the new iron(III) thiolate complexes [CpFe(dppe)SR]PF6. The blue–black paramagnetic complexes were characterized by elemental analysis and IR, EPR and UV–visible spectroscopy. The selective S–H bond cleavage in the thiols suggests a possible utilization of the organometallic iron(II) complexes as inhibitors in some cysteine proteases. The spectroscopic properties of the new complexes have been compared with those of other Fe–S models as well ­as with Fe–S proteins. Copyright © 2000 John Wiley & Sons, Ltd.