Reactions of {(C 6 F 5 )Pt[S(CH 2 CH 2 -) 2 ](μ-Cl)} 2 and R 3 P yield the bis(phosphine) species trans -(C 6 F 5 )(R 3 P) 2 PtCl [R = Et ( Pt'Cl ), Ph, ( p -CF 3 C 6 H 4 ) 3 P; 88-81 %]. Additions of Pt'Cl and H(C≡C) n H ( n = 1, 2; HNEt 2 , 20 mol % CuI) give Pt'C 2 H (37 %, plus Pt'I , 16 %) and Pt'C 4 H (88 %). Homocoupling of Pt'C 4 H under Hay conditions (O 2 , CuCl, TMEDA, acetone) gives Pt'C 8 Pt' (85 %), but Pt'C 2 H affords only traces of Pt'C 4 Pt' . However, condensation of Pt'C 4 H and Pt'Cl (HNEt 2 , 20 mol % CuI) yields Pt'C 4 Pt' (97 %). Hay heterocouplings of Pt'C 4 H or trans -( p -tol)(Ph 3 P) 2 Pt(C≡C) 2 H ( Pt*C 4 H ) and excess HC≡CSiEt 3 give Pt'C 6 SiEt 3 (76 %) or Pt*C 6 SiEt 3 (89 %). The latter and wet n -Bu 4 N + F - react to yield labile Pt*C 6 H (60 %). Hay homocouplings of Pt*C 4 H and Pt*C 6 H give Pt*C 8 Pt* (64 %) and Pt*C 12 Pt* (64 %). Reaction of trans -(C 6 F 5 )( p -tol 3 P) 2 PtCl ( PtCl ) and HC≡CH (HNEt 2 , 20 mol % CuI) yields only traces of PtC 2 H . However, an analogous reaction with HC≡CSiMe 3 gives PtC 2 SiMe 3 (75 %), which upon treatment with silica yields PtC 2 H (77 %). An analogous coupling of trans -(C 6 F 5 )(Ph 3 P) 2 PtCl with H(C≡C) 2 H gives trans -(C 6 F 5 )(Ph 3 P) 2 Pt(C≡C) 2 H (34 %). Advantages and disadvantages of the various trans -(Ar)(R 3 P) 2 Pt end-groups are analyzed.
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Macrocyclic Complexes Derived from Four cis ‐L 2 Pt Corners and Four Butadiynediyl Linkers; Syntheses, Electronic Structures, and Square versus Skew Rhombus Geometries
Abstract The dialkyl malonate derived 1,3‐diphosphines R2C(CH2PPh2)2(R=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–dare also available from2 a–dand excess 1,3‐butadiyne in the presence of CuI (cat.) and excess HNEt2(87–65 %). Under similar conditions,2and3react 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,bshow skew rhombus as opposed to square Pt4geometries. The NMR and IR properties of4 a–fare 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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- PAR ID:
- 10249053
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Chemistry – A European Journal
- Volume:
- 27
- Issue:
- 39
- ISSN:
- 0947-6539
- Page Range / eLocation ID:
- p. 10021-10039
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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