| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2004: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2003: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Research Abstract |
Metallaphosphaheterocycle is a kind of metalloligand in which a metal-phosphorus covalent bond is incorporated in the ring. The ligand is expected to coordinate to a variety of metal centers through lone pair electrons on the phosphorus center to form heterodinuclear complexes in which two metal centers are located in close proximity.
A platinum or palladium fragment was inserted into a phosphorus-carbon bond of phosphorus-bridged [1]ferrocenophane and naphtho[1,8-b,c]phosphete coordinating to a W(CO)_5 fragment. The metallaphosphaheterocycle thus formed was bonded to the W(CO)_5 fragment to form expected heterodinuclear framework. It was found that a ligand located between two metal centers of the dinuclear complex readily dissociates from the platinum or palladium center to form a vacant coordination site.
A new phosphaheterocycle in which a PhP-PPh bond bridges 1,8-positions of naphthalene, 1,2-dihydro-1,2-diphenyl-naphtho[1,8-cd]-1,2-diphosphole (1), was prepared and used as a bridging ligand for the preparation of dinuclear group 6 metal complexes (OC)_5M(μ-1)M(CO)_5 (M=W(2a),Mo(2b),Cr(2c)).
Photolysis of PPh-bridged [1]ferrocenophane (3)in ether gave PPh-bridged [1.1]ferrocenophane(4). After subsequent sulfurization of the reaction mixture with elemental sulfur, both syn and anti isomers of P(S)Ph-bridged [1.1]ferrocenophane (5)were successfully isolated and characterized by X-ray analysis. Upon heating, anti-3 isomerizes to syn-3, indicating thermodynamic stability of syn-3 over anti-3. A potential utility of syn-3 as a ligand was demonstrated by the formation of [CoCl_2(syn-2)](5)through a reaction of syn-3 with CoCl_2. The X-ray structure of 5 showed a novel chelate framework in which two phosphorus donor atoms are linked doubly with two ferrocene chelates.
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