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Ladder-like heteropolynuclear assemblies via cyanido bridges and platinum(II)–thallium(I) bonds: structural and photophysical properties.
- Source :
- Dalton Transactions: An International Journal of Inorganic Chemistry; 5/14/2024, Vol. 53 Issue 18, p7788-7800, 13p
- Publication Year :
- 2024
-
Abstract
- We describe the mononuclear anionic cyanido-pentafluorophenyl complexes, (NBu<subscript>4</subscript>)[Pt(C^N)(C<subscript>6</subscript>F<subscript>5</subscript>)(CN)] [C^N = 7,8-benzoquinolate (bzq) 1, 2-(2,4-difluorophenyl)pyridinate (dfppy) 2] and the heteropolynuclear derivatives [{Pt(C^N)(C<subscript>6</subscript>F<subscript>5</subscript>)(CN)}Tl] (C^N = bzq 3, dfppy 4). These complexes were synthesized via a two-step modular synthesis by reaction of the corresponding potassium salts K[Pt(C^N)(C<subscript>6</subscript>F<subscript>5</subscript>)(CN)], prepared in situ from [Pt(C^N)(C<subscript>6</subscript>F<subscript>5</subscript>)(DMSO)] and KCN in acetone/H<subscript>2</subscript>O, with TlPF<subscript>6</subscript>. The structures of {[Pt(bzq)(C<subscript>6</subscript>F<subscript>5</subscript>)(CN)Tl]·THF}<subscript>n</subscript> (3·THF)<subscript>n</subscript> and [{Pt(dfppy)(C<subscript>6</subscript>F<subscript>5</subscript>)(CN)}Tl]<subscript>4</subscript>·dioxane [4]<subscript>4</subscript>·dioxane, determined by X-ray crystallography, confirm the presence of Pt(II)–Tl(I) bonds [2.9795(6)–3.0736(3) Å], but in the dfppy complex, the incorporation of dioxane, causes a significant structural change. Thus, whereas [3·THF]<subscript>n</subscript> achieves a bent-ladder shape extended double chain Tl⋯[Pt⋯Tl]<subscript>n</subscript>⋯Pt supported by lateral bridging [Pt](μ-CN)[Tl] ligands, [4]<subscript>4</subscript>·dioxane is formed by discrete Pt<subscript>4</subscript>Tl<subscript>4</subscript> rectangular aggregates stabilized by [Pt](μ-CN)[Tl] and Pt⋯Tl bonds, which are connected by dioxane bridging molecules through Tl⋯O(dioxane) additional contacts. Solid state emissions are redshifted compared with the mononuclear derivatives 1 and 2 and have been assigned, with the support of theoretical calculations on Pt<subscript>4</subscript>Tl<subscript>4</subscript> models, to metal–metal′-to-ligand charge transfer (<superscript>3</superscript>MM′LCT [d/s σ*(Pt, Tl) → π*(C^N)]) for 3 and mixed <superscript>3</superscript>MM′LCT/<superscript>3</superscript>IL for 4. In fluid THF solution, the complexes are not emissive. At 77 K, 3 and 4 exhibit bright emissions attributed to the formation of bimetallic [{Pt(C^N)(C<subscript>6</subscript>F<subscript>5</subscript>)(CN)}Tl(THF)<subscript>x</subscript>], and anionic [Pt(C^N)(C<subscript>6</subscript>F<subscript>5</subscript>)(CN)]<superscript>−</superscript> fragments. Furthermore, both 3 and 4 exhibit a reversible mechanochromism with a red shift of the emissions upon crushing, suggesting some degree of shortening of metal–metal separation. Finally, complex 3 shows solvatochromic behavior with color/luminescence changes by treatment with a drop of MeOH, CH<subscript>2</subscript>Cl<subscript>2</subscript>, THF or Et<subscript>2</subscript>O, with shifts from 583 in 3-MeOH to 639 nm in 3-THF. However, 4 only demonstrates a bathochromic response to MeOH. [ABSTRACT FROM AUTHOR]
- Subjects :
- PLATINUM
X-ray crystallography
DIOXANE
REDSHIFT
POTASSIUM salts
LUMINESCENCE
Subjects
Details
- Language :
- English
- ISSN :
- 14779226
- Volume :
- 53
- Issue :
- 18
- Database :
- Complementary Index
- Journal :
- Dalton Transactions: An International Journal of Inorganic Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 177090819
- Full Text :
- https://doi.org/10.1039/d4dt00674g