15279-67-1Relevant articles and documents
Sonochemistry of Mn2(CO)10 and Re2(CO)10
Suslick, Kenneth S.,Schubert, Paul F.
, p. 6042 - 6044 (1983)
Irradiation of liquids with high-intensity ultrasound creates, via cavitation, localized hot spots with transient pressures of > 300 atm and temperatures ca. 3000 K.We report the first studies of the chemical effects of the ultrasound on Mn2(CO)10, MnRe(C
Solid-liquid reactions of manganese and cobalt carbonyl anions with alkyl halides containing β-hydrogens or -halogens
Kovács, István,Ungváry, Ferenc,Garst, John F.
, p. 389 - 396 (2008/10/08)
Heterogeneous reactions afforded the first detection (by IR and NMR spectroscopy) of a secondary (η1-allyl)manganese carbonyl complex, CH3CH=CHCH(CH3)Mn(CO)5, which results from the reaction of solid NaMn(CO)5 with 4-bromo-2-pentene in benzene or in saturated hydrocarbons at temperatures up to 5°C. The analogous reaction of NaCo(CO)4 gives CH3-CH=CHCH(CH3)C(O)Co(CO)4, the product of CO insertion into CH3CH=CHCH(CH3)Co-(CO)4, which constitutes approximately 10% (by IR spectroscopy) of the equilibrium mixture with CH3CH=CHCH(CH3)C(O)Co(CO)4 under CO at 1 atm and 5°C. Addition of PPh3 to this mixture leads to the formation of isolable CH3CH=CHCH(CH3)C(O)Co(CO)3PPh3. Similar reactions of 4-bromo-2-pentene with NaMn(CO)4PPh3 and NaCo(CO)3PPh3 do not give metal-carbon-bonded species, nor do room-temperature reactions of 4-bromo-2-pentene with NaMn-(CO)5 and NaCo(CO)4. Instead, the products include 2-pentenes, 1,3-pentadienes, 4,5-dimethyl-2,6-octadiene isomers, BrMn(CO)5, Mn2(CO)10, Co2(CO)8, and η3-(CH3CHCHCHCH3)Co(CO)3. Reactions of dimethyl chlorosuccinate, ethyl 2-bromopropionate, methyl 3-bromopropionate, and dimethyl dibromosuccinate with NaMn(CO)5 and NaCo(CO)4 give varying amounts of alkylmetal carbonyl compounds and products of β-elimination. The characteristics of these transformations suggest radical mechanisms initiated by single electron transfer (SET). Radical pairs formed by SET are implicated as intermediates in both substitutions and eliminations.
Solution Homolytic Bond Dissociation Energies of Organotransition-Metal Hydrides
Tilset, Mats,Parker, Vernon D.
, p. 6711 - 6717 (2007/10/02)
The homolytic bond dissociation energies (BDEs) of the mononuclear metal carbonyl hydride complexes (η5-C5H5)M(CO)3H (M = Cr, Mo, W), (η5-C5Me5)Mo(CO)3H, (η5-C5H5)W(CO)2(PMe3)H, (η5-C5H5)M(CO)2H (M = Fe, Ru), H2Fe(CO)4, Mn(CO)4PPh3H, Mn(CO)5H, Re(CO)5H, and Co(CO)3LH (L = CO, PPh3, P(OPh)3) have been estimated in acetonitrile solution by the use of a thermochemical cycle that reguires knowledge of the metal hydride pKa and the oxidation potential of its conjugate base (anion).The BDE values obtained by this method fall in the range 50-67 kcal/mol.In mostcases, these results agree well with literature data.Our data provide strong support for the common assumption that the M-H bond energies are greater for third-row and for second-row metals than for first-row metals, the difference being 5-11 kcal/mol.Effects of neither phosphine or phosphite substitution nor permethylation of the cyclopentadienyl ring on the M-H bond energies could be detected within the error limits of the method.The results are discussed in relation to previous M-H BDE estimates and metal hydride reactivity patterns.
