Highly reduced organometallics. 20. The first general synthetic route to zerovalent titanium carbonyls. Synthesis and properties of Ti(CO)/sub 5/(Me/sub 2/PCH/sub 2/CH/sub 2/PMe/sub 2/)
Synthetic procedures developed in this study provide the first general route to zerovalent titanium carbonyls and should facilitate future investigations in this relatively unexplored area of organotitanium chemistry. Sodium naphthalenide reductions of TiCL/sub 4/(THF)/sub 2/ (THF = tetrahydrofuran), in the presence of 2.1-2.3 equiv of Me/sub 2/PCH/sub 2/CH/sub 2/PMe/sub 2/ (dmpe) in THF at -70 to -80/sup 0/ under argon, followed by carbonylation at atmospheric pressure provide 70-80% isolated yields of the previously known but relatively inaccessible Ti(CO)/sub 3/(dmpe)/sub 2/. Under a carbon monoxide atmosphere at room temperature within 3 h, the latter is partially converted to Ti(CO)/sub 5/(dmpe), the initial example of a pentacarbonyltitanium species. Addition of about 2 equiv of BH/sub 3/ x THF to the Ti(CO)/sub 3/(dmpe)/sub 2//Ti(CO)/sub 5/(dmpe) mixture under a CO atmosphere in THF binds free dmpe as dmpe x 2BH/sub 3/ and causes disappearance of all Ti(CO)/sub 3/(dmpe)/sub 2/, thereby allowing the isolation of substantially pure Ti(CO)/sub 5/(dmpe). The latter is a bright red crystalline material that decomposes within hours at room temperature and has been characterized by infrared, /sup 13/C, /sup 31/P, and /sup 1/H NMR spectroscopy. Unlike Ti(CO)/sub 3/(dmpe)/sub 2/, the pentacarbonyl compound is quite reactive toward a variety of main group nucleophiles and thereby represents the first accessible synthetic equivalent of the unknown Ti(CO)/sub 7/. Its reactions with 1,1,1-tris(dimethylphosphinomethyl)ethane (trmpe), sodium cyclopentadienide, sodium indenide, and potassium hydrotris(1-pyrazolyl)borate ((HB(Pz)/sub 3/)Ti(CO)/sub 4//sup -/.
- Research Organization:
- Univ. of Minnesota, Minneapolis (USA)
- OSTI ID:
- 7247306
- Journal Information:
- J. Am. Chem. Soc.; (United States), Vol. 110:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CARBONYLS
CHEMICAL PREPARATION
CHEMICAL PROPERTIES
ORGANOMETALLIC COMPOUNDS
TITANIUM COMPOUNDS
CHEMICAL REACTION YIELD
EXPERIMENTAL DATA
DATA
INFORMATION
NUMERICAL DATA
ORGANIC COMPOUNDS
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
YIELDS
400201* - Chemical & Physicochemical Properties