Syntheses, Crystal Structures, Properties And Supramolecular Chemistry Of Naphtho Crown Ether Complexes

In recent years, the crystal engineering of coordination polymers has become a hot topic in modern chemistry including coordination chemistry, supramolecular chemistry, material science, life sciences and so on. It is also becoming an increasing popular research field because the coordination polymers have interesting physical properties such as electrical conductivity, magnetism, nonlinear optical properties and potential applications in separation, catalyst, physical devices, biomaterial, drug design and so on. As the organic spacers and with the help of other building blocks, crown ethers or crown ether cations, especially those having aromatic moieties, can form one-or multi-dimensional polymeric superstructures by coordination bonds, H-bonds, Ï€?Ï€stacking, cation?Ï€interactions and other weak interactions. The reports concerning complexes of naphtho crown ethers (N15C5, N18C6 and N18C6) are few, so far, there are only four complexes determined by X-ray single crystal analysis. On the basis of our previous work, we expect that the naphtho crown ethers should be used to achieve novel crown ether-metal coordination polymers. For the naphtha crown ethers contain large aromatic group (naphthylene), which may easily present novel non-covalent forces in crystal such as Ï€?Ï€stacking, cation?Ï€interactions and so on, occurred between themselves or with the guest molecules. So, we carried out our work to synthesize crown ether complexes by the reaction of naphtha crown ethers with alkali metal salts of size-fitted inorganic complex anions or other alkali metal salts. 24 complexes containing naphtha crown ethers were obtained, which were all determined by single crystal X-ray diffraction. Their crystal structures, properties and supramolecular information were studied in this work. The four sections of this thesis are listed as follows. 1. The synthesis of N15C5, N18C6 and N18C6 were carried out and afforded pure crown ether products, which were all characterized by elemental analysis, FT-IR spectra, 1H NMR and 13C NMR. The yield of N15C5 is 20% higher than that of other reports. The synthesis and purification of DN18C6 were mastered after several failures and we obtained some valuable experiences. 2. The reactions of N15C5 with the sodium salts of inorganic complex anions afforded 13 new complexes, namely [Na(N15C5)]₂[M(SCN)₄] (M = Pd(1), Pt(2)), [Na(N15C5)₂]₂[M(mnt)₂] (M = Ni(3), Pd(4), Pt(5)) , [Na(N15C5)]2[M(mnt)2] (M = Ni(6), Cu(7)), [Na(N15C5)]2[M(i-mnt)2] (M = Ni(8), Pd(9), Pt(10), Cu(11)), [Na2(N15C5)2(NO3)] (12) and [Na2(N15C5)2(NO3)][Cu(NO3)3(H2O)] (13). The complexes were characterized by elemental analysis, FT-IR spectra, UV-vis spectra and single crystal X-ray diffraction. The structure analyses reveal that both 1 and 2 are assembled into zigzag chains by the strong intermolecular Ï€?Ï€stacking interactions. The molecules of complexes 3?5 are linked into 2D networks by Ï€?Ï€stacking interactions and weak H-bonds. Complexes 6 and 7 both display a corrugated 2D sheet constructed by Na?N bonds. Complexes 8?11 have the isomorphous 1D polymeric structures containing S···C and S···πinteractions, which all look like a "train"and are constructed by Na?N bonds. A 1D zigzag chain assembled by C?H···πinteractions and H-bonds is displayed in complex 13. The study results indicate that the amount of crown ether used in the synthesis much affects the final composition and solid-structure of the target complexes. It also shows an influence of structural features of the complex cations and anions on final crystal structures of the complexes. The Ï€?Ï€stacking interactions between the naphthylene groups in the complexes were studied by single crystal X-ray diffraction. The results show that complexes 1 and 2 afford a parallel "face-to-face"stacking model. The stacking naphthylene groups in complexes 3?5 are slip and the contacts are weak. There are only edge-to-edge interactions for the stacking naphthylene groups in complexes 6 and 7. Moreover, in complexes 13, the stacking naphthylene moieties are T-shape arrayed. 3. The reactions of N18C6 with the potassium salts of inorganic complex anions afforded six crown ether-metal complexes, namely [K(N18C6)]2[M(SCN)4] (M = Pd(14), Pt(15)), {[K(N18C6)]2(CH3CN)}[Ni(mnt)2] (16), [K(N18C6)]2[M(i-mnt)2] (M = Ni(17), Pd(18), Pt(19)). The complexes were characterized by elemental analysis, FT-IR spectra, UV-vis spectra and single crystal X-ray diffraction. The structure analyses reveal that the molecules of complexes 14?19 are all assembled into 2D networks by the K?O or K?N interactions and the Ï€?Ï€stacking interactions. The [K(N18C6)]+complex cations afford two kinds of joint points, one is the potassium ions which link the complex molecules into 1D chains by the K?O or K?N bonds, the other is the naphthylene moieties which pack the 1D chains into 2D structure through inter-chain Ï€?Ï€stacking interactions. The Ï€?Ï€stacking interactions between the naphthylene groups in 14?19 were studied by single crystal X-raydiffraction. The results show that complexes 14 and 15 afford a "parallel displaced"stacking model with the stacking nature of Ï€?σattraction. The stacking models of naphthylene group in complexes 16?19 are similar and can be described as a "parallel offset face-to-face"stacking model. The significant Ï€?Ï€interactions mainly take place between two stacking inner six-member rings of the stacking naphthylene groups. The CV of 16 displays a reversible process corresponding to the [Ni(mnt)2]-/ [Ni(mnt)2]2-reaction. 4. Five complexes, [Na(DN18C6)(H2O)2][Na(DN18C6)(H2O)][(BPh4)2](20), [K(DN18C6)(C2H5OC2H5)][(BPh4)] (21), [K(DN18C6)](SCN) (22), [NH4(DN18-C-6)]2 [Pd(SCN)4](23) and [(LH)(DN18C6)2][ClO4]·4CH3CN (24) (L = 2-aminopyrimidine), were synthesized and characterized by elemental analysis, FT-IR spectra and single crystal X-ray diffraction. The structure analyses reveal that there are cation?Ï€interactions in these complexes. The Ï€refers to the naphthylene group and the cations refer to Na+ (20), K+ (21, 22), NH4+ (23) and LH+ (24, L = 2-aminopyrimidine). Complexes 24 displays a host-guest 2:1 sandwich structure, the guest cation (LH+) is included by two host molecules (DN18C6). In this inclusion structure, there are multiple recognition forces, the H-bonds and the cation?Ï€interactions. The synthesis, crystal structures, properties and supramolecular information of naphtho crown ether complexes were studied in this thesis and the results show some synthesis rules and structural features of the complexes. It was paid much attention to study the molecular self-assembly in the crystal of naphtha crown ether complexes. All the studies may not only endow crown ether chemistry with new knowledge but also afford valuable supports for the design and synthesis of crown ether-metal coordination polymers.