ISSN:
0009-2940
Keywords:
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Dicarbonyl(π-pentamethylcyclopentadienyl)(trifluoromethyl isocyanide)manganese (4) has been synthesized by reaction of Cp*Mn(CO)2(η2-C8H14) (Cp*=(CH3)5C5) (3) with trifluoromethyl isocyanide (1). Cp*Mn(CO)2(CNCH3) (7) has been obtained from Cp*Mn-(CO)2(THF) (5) and CH3NC (6). Cp*Mn(CO)2(CS) (9) is formed in the reaction of 3 with CS2 (8) in the presence of triphenylphosphane. Photolysis of Cp*Mn(CO)3 (2) in the presence of excess 1 yields Cp*Mn(CNCF3)3 (10) as the final product. All these (pentamethylcyclopentadienyl)(trifluoromethyl isocyanide)manganese complexes exhibit infrared absorption bands at low wave-numbers for the NC vibrations and at high wave-numbers for the CO vibrations. The force constant of the CO vibration indicates that the trifluoromethyl isocyanide ligand is an extremely strong π-accepting ligand which exceeds even the thiocarbonyl ligand in its π-accepting ability.
Notes:
Die Synthese von Dicarbonyl(π-pentamethylcyclopentadienyl)-(trifluormethylisocyanid)mangan (4) gelingt durch Umsetzung von Cp*Mn(CO)2(η2-C8H14) (Cp*=(CH3)5C5) (3) mit Trifluormethylisocyanid (1). Cp*Mn(CO)2(CNCH3) (7) wird aus Cp*Mn-(CO)2(THF) (5) und CH3NC (6) erhalten. Cp*Mn(CO)2(CS) (9) Bildet sich aus 3 und CS2 (8) in Gegenwart von Triphenylphosphan. Cp*Mn(CNCF3)3 (10) entsteht bei der Photolyse von Cp*Mn(CO)3 (2) mit überschüssigem 1. Alle (Pentamethylcyclopentadienyl)(trifluormethylisocyanid)mangan-Komplexe zeigen niedrigliegende NC-Valenzschwingungen und hochliegende CO-Valenzschwingungen. Aus den Kraftkonstanten der CO-Valenzschwingung läßt sich die relative π-Akzeptorstärke des Trifluormethylisocyanid-Liganden abschätzen, die sogar die des Thiocarbonylliganden übertrifft.
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19871200309
Permalink
