Palladium Complexes of a Phosphorus Ylide with Two Stabilizing Groups: Synthesis, Structure, and DFT Study of the Bonding Modes
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- 作者：Larry R. Falvello ; Juan Carlos Giné ; s ; Jorge J. Carbó ; Agustí ; Lledó ; s ; Rafael Navarro ; Tatiana Soler ; Esteban P. Urriolabeitia
- 刊名：Inorganic Chemistry
- 出版年：2006
- 出版时间：August 21, 2006
- 年：2006
- 卷：45
- 期：17
- 页码：6803 - 6815
- 全文大小：302K
- 年卷期：v.45,no.17(August 21, 2006)
- ISSN：1520-510X
文摘
The phosphorus ylide ligand [Ph3P=C(CO2Me)C(=NPh)CO2Me] (L1) has been prepared and fully characterizedby spectroscopic, crystallographic, and density functional theory (DFT) methods (B3LYP level). The reactivity of L1toward several cationic PdII and PtII precursors, with two vacant coordination sites, has been studied. The reactionof [M(C
X)(THF)2]ClO4 with L1 (1:1 molar ratio) gives [M(CX)(L1)]ClO4 [M = Pd, CX = C6H4CH2NMe2 (1),S-C6H4C(H)MeNMe2 (2), CH2-8-C9H6N (3), C6H4-2-NC5H4 (4), o-CH2C6H4P(o-tol)2 (6), 
3-C3H5 (7); M = Pt, CX= o-CH2C6H4P(o-tol)2 (5); M(CX) = Pd(C6F5)(SC4H8) (8), PdCl2 (9)]. In complexes 1-9, the ligand L1 bondssystematically to the metal center through the iminic N and the carbonyl O of the stabilizing CO2Me group, as isevident from the NMR data and from the X-ray structure of 3. Ligand L1 can also be orthopalladated by reactionwith Pd(OAc)2 and LiCl, giving the dinuclear derivative [Pd(
-Cl)(C6H4-2-PPh2=C(CO2Me)C(CO2Me)=NPh)]2 (10).The X-ray crystal structure of 10 is also reported. In none of the prepared complexes 1-10 was the C
atom foundto be bonded to the metal center. DFT calculations and Bader analysis were performed on ylide L1 and complex9 and its congeners in order to assess the preference of the six-membered N,O metallacycle over the four-membered C,N and five-membered C,O rings. The presence of two stabilizing groups at the ylidic C causes areduction of its bonding capabilities. The increasing strength of the Pd-C, Pd-O, and Pd-N bonds along withother subtle effects are responsible for the relative stabilities of the different bonding modes.
X)(THF)2]ClO4 with L1 (1:1 molar ratio) gives [M(CX)(L1)]ClO4 [M = Pd, CX = C6H4CH2NMe2 (1),S-C6H4C(H)MeNMe2 (2), CH2-8-C9H6N (3), C6H4-2-NC5H4 (4), o-CH2C6H4P(o-tol)2 (6), 3-C3H5 (7); M = Pt, CX= o-CH2C6H4P(o-tol)2 (5); M(CX) = Pd(C6F5)(SC4H8) (8), PdCl2 (9)]. In complexes 1-9, the ligand L1 bondssystematically to the metal center through the iminic N and the carbonyl O of the stabilizing CO2Me group, as isevident from the NMR data and from the X-ray structure of 3. Ligand L1 can also be orthopalladated by reactionwith Pd(OAc)2 and LiCl, giving the dinuclear derivative [Pd(-Cl)(C6H4-2-PPh2=C(CO2Me)C(CO2Me)=NPh)]2 (10).The X-ray crystal structure of 10 is also reported. In none of the prepared complexes 1-10 was the C atom foundto be bonded to the metal center. DFT calculations and Bader analysis were performed on ylide L1 and complex9 and its congeners in order to assess the preference of the six-membered N,O metallacycle over the four-membered C,N and five-membered C,O rings. The presence of two stabilizing groups at the ylidic C causes areduction of its bonding capabilities. The increasing strength of the Pd-C, Pd-O, and Pd-N bonds along withother subtle effects are responsible for the relative stabilities of the different bonding modes.