Chiral cis-Platinum Acetylide Complexes via Diphosphine Ligand Exchange: Effect of the Ligand

Building Blocks for Molecular Polygons Based on Platinum Vertices and Polyynediyl Edges

Reactions of Cl2P(CH2)3PCl2 and p-MgBrC6H4X (X = a/OMe, b/OtBu, c/tBu, d/SiMe3) give the diphosphines (p-XC6H4)2P(CH2)3P(p-C6H4X)2 (1a-d; 47-66%). Additions of 1a,d to (COD)PtCl2 yield (CH2(CH2P(p-C6H4X)2)2)PtCl2 (2a,d; 62-88%), which upon reaction with butadiyne (2 equiv; HNEt2/cat. CuI) give (CH2(CH2P(p-C6H4X)2)2)Pt((C≡C)2H)2 (3a,d; 34-76%). Alternatively, 3a-d can be accessed from trans-(p-tol3P)2Pt((C≡C)2H)2 and 1a-d (30-87%). Reactions of (p-tol3P)2PtCl2 and H(C≡C)2SiR3 (2 equiv, HNEt2/cat. CuI; R = Me/Et/iPr) give trans-(p-tol3P)2Pt((C≡C)2SiR3)2 (77-95%), and subsequent additions of 1a,b,d yield the corresponding adducts (CH2(CH2P(p-C6H4X)2)2)Pt((C≡C)2SiR3)2 (R/X = Me/OMe, 5a; iPr/OMe, 6a; iPr/OtBu, 6b; iPr/SiMe3, 6d; 52-95%) and (for 5a) a luminescent diplatinum byproduct with trans Pt((C≡C)2SiMe3)2 units. 5a and 6b hydrolyze in the presence of F- to 3a,b (92-93%). Reaction of 2a and 3a (HNEt2/cat. CuI) affords the Pt4C16 polygon ([(CH2(CH2P(p-C6H4OMe)2)2)Pt(C≡C)2]4 as an H2NEt2+ Cl- adduct (66%). The 13C{1H} NMR spectra of 3a-d, 5a, and 6a,b,d feature complex AMXX' (CPtPP') spin systems, and simulations allow J values to be extracted. The crystal structures of 2a, 3a,b,d, 5a, and 6a are determined and analyzed.

Wire like diplatinum, triplatinum, and tetraplatinum complexes featuring X[PtCCCCCCCC]mPtX segments; iterative syntheses and functionalization for measurements of single molecule properties

The title complexes are accessed from platinum chloride and Z(CC)₂SiMe₃ (Z = Me₃Sn, H) building blocks via oxidative homocouplings and cross couplings.

Effect of phosphine ligand on the optical absorption/emission properties of platinum-containing conjugated polymers

The λ_max values of platinum-containing poly(phenyleneethynylene)s with aryl groups bonded to P were higher than those with alkyl groups.

Organophosphines in organoplatinum complexes: structural aspects of trans-PtP2C2 derivatives

This review summarized and analyzed the structural parameters of 174 monomeric organoplatinum complexes with an inner coordination sphere of trans-PtP2C2. These complexes crystallized in four crystal systems: hexagonal (x2), orthorhombic (x13), triclinic (x76), and monoclinic (x84). These complexes, on the basis of the coordination mode of the respective donor ligands, can be divided into the seven sub-groups: Pt(PL)2(CL)2, Pt(PL)2(η2-C2L), Pt(η2-P2L)(CL)2, Pt(PL)(η2-P,CL)(CL), Pt(η2-P,CL)2, Pt(η3-P,C,PL)(CL), and Pt(η3-C,P,CL)(PL). The chelating ligands create 4-, 5-, 6-, 16-, 17-, 18-, and 19-membered rings. The total mean values of Pt-L bond distances are 2.055 Å (C) and 2.300 Å (P). There are examples that exist in two isomeric forms and are examples of distortion isomerism. The structural parameters of trans-PtP2C2 are discussed with those of cis-PtP2C2 derivatives.

Our Expedition in Linear Neutral Platinum-Acetylide Complexes: The Preparation of Micro/nanostructure Materials, Complicated Topologies, and Dye-Sensitized Solar Cells

During the past few decades, the construction of various kinds of platinum-acetylide complexes has attracted considerable attention, because of their wide applications in photovoltaic cells, non-linear optics, and bio-imaging materials. Among these platinum-acetylide complexes, the linear neutral platinum-acetylide complexes, due to their attractive properties, such as well-defined linear geometry, synthetic accessibility, and intriguing photoproperties, have emerged as a rising star in this field. In this personal account, we will discuss how we entered the field of linear neutral platinum-acetylide chemistry and what we found in this field. The preparation of various types of linear neutral platinum-acetylide complexes and their applications in the areas of micro/nanostructure materials, complicated topologies, and dye-sensitized solar cells will be summarized in this account.

Chiral tether-mediated stabilization and helix-sense control of complementary metallo-double helices

A series of novel PtII-linked double helices were prepared by inter- or intrastrand ligand-exchange reactions of the complementary duplexes composed of chiral or achiral amidine dimer and achiral carboxylic acid dimer strands joined by trans-PtII-acetylide complexes with PPh3 ligands using chiral and achiral chelating diphosphines. The structure and stability of the PtII-linked double helices were highly dependent on the diphosphine structures. An interstrand ligand exchange took place with chiral and achiral 1,3-diphosphine-based ligands, resulting in trans-PtII-bridged double helices, whose helical structures were quite stable even in dimethyl sulfoxide (DMSO) due to the interstrand cross-link, whereas a 1,2-diphosphine-based ligand produced non-cross-linked cis-PtII-linked duplexes, resulting from an intrastrand ligand-exchange that readily dissociated into single strands in DMSO. When enantiopure 1,3-diphosphine-based ligands were used, the resulting trans-PtII-bridged double helices adopted a preferred-handed helical sense biased by the chirality of the bridged diphosphines. Interestingly, the interstrand ligand exchange with racemic 1,3-diphosphine toward an optically-active PtII-linked duplex, composed of chiral amidine and achiral carboxylic acid strands, was found to proceed in a diastereoselective manner, thus forming complete homochiral trans-PtII-bridged double helices via a unique chiral self-sorting.