- Non-chelating polydentate N -heterocyclic carbenes through assembly approaches
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Bridging-type polydentate N-heterocyclic carbene (NHC) ligands are valuable building blocks for organometallic supramolecules. In order to quickly expand the ligand library of poly-NHC, we have assembled several bi-functional carbene precursors with spiroborate, phthalimide and metal-carboxylate to yield poly-NHC ligands with various denticities and geometries. Condensation of 4,5-dihyxdroxy-N,N′-diaryl-benzimidazolium and arylboronic acids leads to a spiroborate-linked bis-benzimidazolium salt, which can be further deprotonated to give a linear anionic bis-NHC. The second approach utilizes the dehydrative condensation of phthalic anhydride functionalized benzimidazole with poly-anilines to afford a series of poly-benzimidazole compounds, which can be converted into the corresponding poly-nuclear metal-NHC complexes after alkylation and metalation. The introduction of a benzoate group to bi-functional carbene precursor facilitates the assembly of poly-benzimidazolium salts with metal salts leading to MCl2 (M=Zn, Co)-linked C2h symmetric bis-benzimidazoliums and a penta-Zn cluster-linked tetra-benzimidazolium.
- Lin, Ya-Fan,Liu, Chih-Hsun,Hu, Chung-Hao,Chiu, Ching-Wen
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- Non-chelating polydentate N -heterocyclic carbenes through assembly approaches
-
Bridging-type polydentate N-heterocyclic carbene (NHC) ligands are valuable building blocks for organometallic supramolecules. In order to quickly expand the ligand library of poly-NHC, we have assembled several bi-functional carbene precursors with spiroborate, phthalimide and metal-carboxylate to yield poly-NHC ligands with various denticities and geometries. Condensation of 4,5-dihyxdroxy-N,N′-diaryl-benzimidazolium and arylboronic acids leads to a spiroborate-linked bis-benzimidazolium salt, which can be further deprotonated to give a linear anionic bis-NHC. The second approach utilizes the dehydrative condensation of phthalic anhydride functionalized benzimidazole with poly-anilines to afford a series of poly-benzimidazole compounds, which can be converted into the corresponding poly-nuclear metal-NHC complexes after alkylation and metalation. The introduction of a benzoate group to bi-functional carbene precursor facilitates the assembly of poly-benzimidazolium salts with metal salts leading to MCl2 (M=Zn, Co)-linked C2h symmetric bis-benzimidazoliums and a penta-Zn cluster-linked tetra-benzimidazolium.
- Lin, Ya-Fan,Liu, Chih-Hsun,Hu, Chung-Hao,Chiu, Ching-Wen
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p. 613 - 617
(2016/04/20)
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- Syntheses and characterization of four 2D metal-organic networks based on rigid imidazolate/carboxylate functionalized ligand - Effect of the torsion of the ligands on crystal structures and properties
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A series of rigid imidazolate/carboxylate functionalized ligands, X-(5,7-dioxopyrrolo[3,4-f]benzimidazole-6-yl)benzoic acid (X = 4, H 24-DPBB; X = 3, H23-DPBB; X = 2, H22-DPBB) were designed and used for the assemble reactions with Zn2+/Cd 2+/Cu2+ ions. Four compounds, [Zn(4-DPBB)(H 2O)]·DMSO·0.5MeOH (1), [Cd(3-DPBB)(DMA) 1.8(H2O)0.2] (2), [Cu(3-DPBB)(DMSO)(DMA)] (3) and [Cd(2-DPBB)(DMA)2] (4) have been synthesized and structurally characterized (where DMSO = dimethylsulfoxide, DMA = dimethyl acetylamide). Single crystal X-ray analyses show that the four compounds are all based on 3-connected single metal nodes and 3-connected spacers. Compounds 1 and 2 bear a 2D (6, 3)-net structure, while 3 and 4 have a 2D (4, 8)-net. Compared with 2, 3 and 4, 1 exhibits a relatively high thermal stability which is up to ~550 °C. Luminescent analysis indicates that 1 and 2 exhibit linker-localized emissions while 4 has ligand-to-metal charge transfer (LMCT) emission. The effect of the torsion of the ligands on the crystal structures and properties of the four compounds is discussed.
- Yang, Jing-Si,Zhu, Jiang,Liu, Rui-Bin,Ni, Jun,Chang, Zhi-Duo,Hu, Tao,Zhang, Jian-Jun,Meng, Chang-Gong
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p. 117 - 126
(2013/02/23)
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