Synthesis, structures and properties of platinum(ii) complexes of oligothiophene-functionalized ferrocenylacetylene

Abstract

A series of rigid-rod alkynylferrocenyl precursors with oligothiophene (from thiophene to terthiophene) linkage units in the backbone, [(η 5 -C 5 H 5 )Fe(η, have been prepared in moderate to good yields. The ferrocenylacetylene complexes 4a-4c can be used to form a range of stable platinum() alkynyl and bis(alkynylAll these new compounds have been fully characterized by analytical and spectroscopic methods and the molecular structures of the bithienyl-linked complexes [(η2b, 4b, 5b and 6b have been established by X-ray crystallography. Structural analysis of 6b confirms its rigid-rod structural motif, featuring coplanar bithienyl rings and a trans arrangement of the two bithiophene groups. An iron-iron throughspace distance of ca. 32 Å is observed in 6b. Although there is no significant metallocene-metallocene interaction through the alkynyl-platinum-oligothiophene bridge, a slight negative shift of the ferrocene-ferrocenium redox potential in the platinum-containing species indicates some degree of electron delocalization into the platinum segment, in line with the results from theoretical studies. Oxidation of the thiophene units is facilitated by the presence of the platinum centre and increased conjugation in the chain. Results and discussion SynthesisScheme 1 summarizes the reaction steps leading to the new ferrocenyl compounds in this study. 2-Bromo-5-(2-ferrocenylethynyl)-DALTON

Electron‐Transfer Studies of trans‐Platinum Bis(acetylide) Complexes

“…For the synthesis of trans-[Pt(CϵCFc) 2 (PFc m nBu 3-m ) 2 ] (m = 0, 9a; [47] m = 1, 9b; m = 2, 9c), phosphines 3a-3c were treated with cis-[PtCl 2 (SEt 2 ) 2 ] (6) to form platinum complexes of the type [PtCl 2 (PFc m nBu 3-m ) 2 ] (m = 0, cis-7a; [48] m = 1, trans-7b; m = 2, trans-7c; Scheme 2). The subsequent reactions of 7a-7c with cuprous ferrocenyl acetylide (8) afforded the title compounds 9a-9c (Scheme 2).…”

“…The platinum acetylide complexes trans-[Pt(CϵCFc) 2 terized by single-crystal X-ray diffraction. Compounds 7b, 7c, 9b, and 9c exhibit a trans arrangement of the ferrocenylphosphine moieties at the platinum center.…”

“…The peak separation ΔE°Ј 3 again represents an electrostatic stabilization between the ferrocenyl/ Scheme 3. Stepwise oxidation of 9c to afford [Pt(CϵCFc) 2 …”

Syntheses, Structures and Photophysical Properties of Metal Carbonyl Clusters with Dansyl and Acridone Luminophores

“…Addition of polarization functions to C, N and O would increase the number of basis functions by more than a hundred. Previous molecular orbital calculations on other related systems [45,46] showed that the medium-size basis set provides reasonable results. In addition, we are interested in obtaining the qualitative picture of orbital patterns for the clusters and in comparing the relative HOMOϪLUMO gaps.…”

Metall‐Alkinyl‐σ‐Komplexe: Synthesen und Materialien

“…50 auf und kommen als Modellsysteme für molekulare Drähte infrage. [302] In den letzten Jahren wurde über eine Reihe von MetallFerrocenylalkinylkomplexen unter anderem mit Pt II , [295,303,304] Mn I , [305] Ru und Os, [131,[306][307][308][309][310] [Co 2 (CO) 6 ] [276,311,312] und Titanocen berichtet, [313] aus denen durch chemische oder elektrochemische Oxidation zweikernige gemischtvalente Heterometallkomplexe erhältlich sind. [314] Die Systeme lassen sich nach Robin und Day als gemischtvalente Verbindungen der Klasse II einstufen.…”