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Title: 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 af, 94–69 %) orcis‐(R2C(CH2PPh2)2)Pt((C≡C)2H)2(3 af, 97–54 %). Complexes3 adare also available from2 adand 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 af; 89–14 % (64 % avg)), from which ammonium salts such as the co‐product [H2NEt2]+Clare challenging to remove. Crystal structures of4 a,bshow skew rhombus as opposed to square Pt4geometries. The NMR and IR properties of4 afare 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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Award ID(s):
1153085 1900549
NSF-PAR ID:
10249053
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  
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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