The dialkyl malonate derived 1,3‐diphosphines R2C(CH2PPh2)2(R=
- NSF-PAR ID:
- 10454317
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Photochemistry and Photobiology
- Volume:
- 97
- Issue:
- 1
- ISSN:
- 0031-8655
- Page Range / eLocation ID:
- p. 80-90
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract a , Me;b , Et;c ,n ‐Bu;d ,n ‐Dec;e , Bn;f ,p ‐tolCH2) are combined with (p ‐tol3P)2PtCl2ortrans ‐(p‐ tol3P)2Pt((C≡C)2H)2to give the chelatescis ‐(R2C(CH2PPh2)2)PtCl2(2 a –f , 94–69 %) orcis ‐(R2C(CH2PPh2)2)Pt((C≡C)2H)2(3 a –f , 97–54 %). Complexes3 a –d are also available from2 a –d and excess 1,3‐butadiyne in the presence of CuI (cat.) and excess HNEt2(87–65 %). Under similar conditions,2 and3 react to give the title compounds [(R2C(CH2PPh2)2)[Pt(C≡C)2]4(4 a –f ; 89–14 % (64 % avg)), from which ammonium salts such as the co‐product [H2NEt2]+Cl−are challenging to remove. Crystal structures of4 a ,b show skew rhombus as opposed to square Pt4geometries. The NMR and IR properties of4 a –f are similar to those of mono‐ or diplatinum model compounds. However, cyclic voltammetry gives only irreversible oxidations. As compared to mono‐platinum or Pt(C≡C)2Pt species, the UV‐visible spectra show much more intense and red‐shifted bands. Time dependent DFT calculations define the transitions and principal orbitals involved. Electrostatic potential surface maps reveal strongly negative Pt4C16cores that likely facilitate ammonium cation binding. Analogous electronic properties of Pt3C12and Pt5C20homologs and selected equilibria are explored computationally. -
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