Assembling Phthalocyanine Dimers through a Platinum(II) Acetylide Linker

Abstract

Phthalocyanine (Pc) dimers connected through trans-platinum(II) diacetylide linkers have been prepared by reaction of the corresponding ethynylphthalocyanines with trans-bis(triethylphosphine)platinum(II) chloride. Special emphasis was placed on the analysis of the ground- and excited-state features of these compounds in relation to butadiyne-bridged Pc dimers and the corresponding monomers. Both Zn(II)-containing Pc dimers exhibit long-lived triplet excited states. The insertion of σ-bonded trans-platinum(II) diacetylide spacers decoupled the two Pc groups and led to an appreciable acceleration (by a factor of up to 10) of the radiative and nonradiative decay rate of the singlet and triplet excited states.

(24-Сrown-8)-Linked Dimeric Phthalocyanines and Their Metal Complexes

“…Various molecular fragments were used as linkers in these types of compounds. Thus, substituted aromatic moieties, [10,24,36] ethyleneglycol and thia-ethyleneglycol, [37] ferrocene, [38] metal cation, [39] acetylene, [40] calixarenes, [41,42] alkyl chain, [12] annulated arenes [9,[43][44][45] were applied as spacers.…”

Assembling a Phthalocyanine and Perylenediimide Donor–Acceptor Hybrid through a Platinum(II) Diacetylide Linker

“…IR spectroscopy of compounds containing the platinum acetylide moiety, namely, Pc 8 and Pc‐Pt‐PDI conjugate 1 , showed the ν CC stretching band at 2108 and 2066 cm −1 , respectively, in the same spectral region, but considerably more intense than that shown by Pc‐PDI conjugate 2 (2189 cm −1 ) lacking the platinum ion (Figures S23, S31, and S35 in the Supporting Information). As for dimeric Pc platinum diacetylide complexes10 and conjugated Pc‐PDI assemblies,9a the 1 H NMR spectra of Pt complexes 8 and 1 and dyad 2 displayed very broad signals (Figures S22, S27, and S32 in the Supporting Information). Compound 1 maintains the trans PPtP configuration of the Pt(PEt 3 ) 2 Cl 2 precursor, as evidenced by its 31 P NMR spectrum.…”

“…The electrochemistry of 1 , 8 , and 2 was inspected by using cyclic voltammetry (CV) and square‐wave voltammetry (SWV) in dichloromethane (Figure S36 in the Supporting Information). The oxidation and reduction potentials of 1 and 2 were compared with those of 8 and those reported for PDI derivatives 10 and 11 20 (Figure 4) and Pc 7 10…”

“…In this hybrid, two ZnPc rings were connected to the bay region of a PDI by means of triple bonds. Furthermore, we have studied the trans ‐platinum(II) diacetylide moiety as a linker of Pc subunits in Zn II phthalocyanine dimers (Pc‐Pt‐Pc) 10. Insertion of such a σ‐bonded spacer between two Pcs decouples the two macrocycles from each other and induces, through a heavy atom effect, fast intersystem crossing for the singlet excited state to triplet excited state.…”

Geometric Influence on Intramolecular Photoinduced Electron Transfer in Platinum(II) Acetylide‐Linked Donor–Acceptor Assemblies

“…Later, Okada developed a D– cis ‐Pt–A system, which exhibited long lifetimes for the charge separated state (CS; 839 ns in toluene), thus minimizing the SOC effect 28. 29 These multicomponent systems σ‐bonded to the Pt II centers have been connected to different electron donors, such as porphyrins,30 phthalocyanines31 or bodipy32 moieties resulting in efficient energy transfer processes. Triphenylamines are one of the most used moieties in D–B–A conjugated systems33 because of their three‐dimensional propeller structure, which is beneficial for improving solution processability, strong electron‐donor properties and excellent hole‐injection and transport properties via radical cation species.…”