Synthesis, Assembly And Properties Of N-heterocycle And Carboxylate Functionalized Silanes

Functionalized silanes are defined as the small organosilicon compounds with functional groups and can be divided into two types:?-type and heteroatom-type. Organosilicon compounds possess many unique characteristics because silicon atom can provide 3d unoccupied orbitals. On the one hand, they can serve as ligands owing to 7r-type and heteroatom-type groups providing delocalized electron and isolated electron, and can be interacted with metal ions to form small metal complexes or coordination polymers through coordination assembly. Compared to the common metal complexes, these silicon-based metal complexes have many novel structures and better optical, electronic and magnetic properties and could be potentially applied in many fields, such as electroluminescent devices, sensor technology et al owing to the unique structure and electronic properties of silicon atom. On the other hand, compared to conventional carbon compounds, functionalized silanes have many advantages, such as more accessible synthesis, high thermal stability and high color purity. Thus they have been applied in extensive areas, including organic light emitting devices, chemical sensors or biosensors et al. In this dissertation, investigations have been carried out and focused on the synthesis, assembly and properties of nitrogen-heterocycle and carboxylate functionalized silanes. The main contents are as follows:1. A series of precursors of phenyl-bridged functionalized silanes—bromophenyl silanes have been synthesized, including products 1?7 with bromine in the p- position of silicon, products 8-11 with bromine in the m- position of silicon and pheyl-bridged product 13, then characterized by FTIR?1H NMR and 13C NMR. After the effects of different reaction methods on the products have been investigated and a suitable synthetic condition has been chosen as the synthesis of bromophenyl silanes. The condition is using organolithium reagent, anhydrous ether as the reaction solvent and-78?as the reaction temperature.2. Bromophenyl silanes as the starting materials, a series of phenyl-bridged imidazole functionalized silanes, including Bis(4-(1H-imidazol-1-yl)phenyl)dimethyl silane (L1), Tri(4-(1H-imidazol-1-yl)phenyl)methylsilane (L2), Bis(4-(1H-imidazol-1-yl)phenyl)diphenylsilane (L3), Tri(4-(1H-imidazol-1-yl)phenyl)phenylsilane (L4), [Bis(4-(1H-imidazol-1-yl)phenyl)](4-bromophenyl)phenylsilane (L5) and [Tri(4-(1H-imidazol-1-yl)phenyl)](4-bromophenyl)silane (L6) have been synthesized according to Ullmann condensation reaction and characterized by FTIR,1H NMR,13C NMR and mass spectroscopy. The effects of several different reaction systems on productions have been studied and two proper reaction systems have been obtained. They all display high thermal stability, are fluorescent with emission in the region of violet to blue, and possess large HOMO-LUMO energy gaps ranging from 4.9585 to 5.1879 eV. Thus they could be potentially used as blue emitters or hole blocking materials in OLEDs. Moreover, the metal ion titrations based on Ag (?) and compounds 1-4 reveal that these ligands perform distinguishable fluorescence response with increase of Ag (?) ions.3. Bromophenyl silanes as the starting materials, a series of phenyl-bridged nitrogen-heterocycle functionalized silanes have been synthesized via Ullmann condensation reaction, including Bis(4-(1H-pyrazol-1-yl)phenyl)dimethylsilane (L8), Bis(3-(1H-pyrazol-1-yl)phenyl)dimethylsilane (L9), Tri(4-(1H-pyrazol-1-yl)methyl silane (L10), Bis(4-(1H-benimidazol-1-yl)phenyl)dimethylsilane (L11), Bis(3-(1H-benimidazol-1-yl)phenyl)dimethylsilane (L12), Bis(4-methyl-(1H-imidazol-1-yl) phenyl)dimethylsilane (L13), (3-(1H-imidazol-1-yl)phenyl)trimethylsilane (L14), Bis(3-(1H-imidazol-1-yl)phenyl)dimethylsilane (L15), Tri(4-(1H-imidazol-1-yl) phenyl)methylsilane (L16) and Bis(4-(1H-imidazol-1-yl)phenyl)vinylmethylsilane (L17) and then characterized by FTIR,1H NMR,13C NMR and mass spectroscopy. They all display high thermal stability, are fluorescent with emission in the region of violet to blue. Thus they could be potentially used as blue emitters in OLEDs. The investigations on the optical properties of different nitrogen-heterocycle functionalized silanes reveal that three approaches, including high?-conjugated system, multi- functional groups introduced in the compound and functional groups locating in the p- position with phenyl bridging are effective ways to increase the quantum yield of them.4. Based on a semirigid imdazole functionalized silane, Bis(4-(1H-imidazol-1-yl) phenyl)dimethylsilane (L1), five novel coordination polymers, [Ag(Ll)]0.5[Ag(Ll)]2·2.5ClO4·5H2O (CP-1), Ag(Ll)PF6·H2O (CP-2), MnCl2(L1)2 (CP-3), Cu(L1)Br (CP-4) and Cu(L1)Cl (CP-5) have been constructed and the structures were determined by single crystal X-ray diffraction. The results reveal that all of them were built from one-dimensional (1D) chains, which indicate that L1 is an excellent linear ligand. CP-1 is a 3D-braided porous metal-organic framework via self-assembly of two series of 1D polymer chains through both braiding and interpenetrating. CP-1 consists of two distinct kinds of channels with different sizes and shapes along a and b directions occupied by perchlorate anions and water molecules. Complex CP-1 possesses selective anion exchange with PF6- and BF4- anions over CF3SO3-/PF6-/ BF4-. CP-3 contains a 2D layered structure constructed from 1D chains with a 34-memebered macrometallocycle as the subunit. CP-4 and CP-5 belong to 2D layered structure built from 1D zigzag chains, then 3D supramolecular structures are formed through ABAB…stacking between adjacent 2D layers. At last, dynamic and thermodynamic effects on the structures of the coordination polymers are also discussed.5. Six carboxylate functionalized silanes, have been synthesized, including Bis(4-carboxyphenyl)dimethylsilane (L18), Tri(4-carboxyphenyl) methylsilane (L19), Tetra(4-carboxyphenyl)silane (L20), Bis(3-carboxyphenyl)dimethylsilane (L21), Tri (3-carboxyphenyl)methylsilane (L22) and Tetra(3-carboxyphenyl)silane (L23) and then characterized by FTIR,1H NMR,13C NMR and mass spectroscopy. Two synthetic routes on these compounds have been discussed and a suitable route for carboxylate functionalized silanes has been achieved.Based on L22 and L23, two novel coordination polymers, [Cd3(L22)2(Py)4]·4H2O (CP-6) and [Cd4(L23)2(DMF)2(H2O)6(EtOH)]·4DMF (CP-7) have been constructed and their structures were determined by single crystal X-ray diffraction.. CP-6 was obtained from L22 and Cd(NO3)2 through double phase reaction and is a 3D porous (6,3) network containing high disordered octahedral trimetallic secondary buliding units (SBUs). CP-6 consists of square and ellipse channels occupied by water molecules. CP-7 was built from L23 and Cd(NO3)2 through single phase reaction. In CP-7, two nodes based on metal ions exist. One is single Cd(II) and the other is trimetallic SBUs. L23 acts as tetrahedral spacers and forms an 2D (4,4) layered network. A 3D supramolecular structure is formed through ABCD…stacking between 2D layers.