Design, Synthesis And Properties Of Novel Organic-Inorganic Hybrid Intercalation Compounds

In recent years much attention has been drawn to inorganic-organic nanocomposite materials due to their promising applications in many fields. Intercalation of organic species into layered inorganic solids represents one of the useful approaches to design and synthesize some functional and multifunctional materials including optical, electric and magnetic materials.The thesis contains three parts of the research work. The first part (Chapters 2-4) mainly describes the synthesis, structural characterization and properties of some new intercalation compounds based on the host MnPS3. The second part (Chapter 5) describes the synthesis, structural characterization and magnetic properties of a new series of mixed transition metal phosphorus sulfides MnxCd1-xPS3 and two series of intercalates based on these hosts. The third part (Chapter 6) studies the synthesis, structural characterization and magnetic, electrical properties of a series of intercalates based on MoS2. In this thesis, sixteen new compounds have been synthesized including four intercalation compounds of the lamellar MnPS3, three mixed transition metal phosphorus sulfides MnxCd1-xPS3 and six intercalates based on these hosts, and three intercalates based onChapter 1 reviews the recent advances on the intercalation compounds and their promising applications in many fields,especially about the synthetic methods,structures, properties and potential applications of the intercalates based on layered MPS3 and transition metaldichalcogenides. Furthermore,the design strategies and the contents of the thesis are outlined in this chapter.Chapter 2 describes the synthesis, structural characterization and some solid-state physical properties of a new intercalation compound of TTM-TTF (tetrathiomethyl tetrathiafulvalene) into MnPS3, which was obtained by treating the pre-intercalate Mn0.83PS3(bipy)0.51with (TTM-TTF)Ix in acetonitrile. Compared with pure MnPS3, the lattice spacing is increased by about 3.5 A, which means that the molecular ring plane of the guest is almost parallel to the layer of the host. From the IR spectra, it can be seen that the intercalate exhibits the characteristic absorptions of both neutral TTM-TTF and cationic TTM-TTF. The room-temperature electrical conductivity of the compressed pellet of Mn0.83PS3(bipy)0.51 is around 4.0x 10-7 S/cm, which is a little bettsr than that of the pristine MnPS3. Its magnetic property is studied with SQUID. Three magnetic transitional periods occur in the range between 40 K and 5 K. The first magnetic transition at 40 K indicates a weak ferromagnetic transition, but in the range of 30 K to 5 K, the antiferromagnetism plays the main role in it. And anothermagnetic transition at 5 K indicates that the new intercalate exhibits bulk spontaneous magnetism below 5 K.In Chapter 3, a new series of intercalation compounds, in which a series of cationic complexes [M(Salen)]+ (M = Mn, Fe, Co) are intercalated into the lamellar MnPS3, have been synthesized. Compared with MnPS3, the lattice expansion (Ad) of 9-10 A for [Fe(Salen)]0.56Mno.72PS3-0.5H2O and [Mn(Salen)]0.26Mn0.87PS3-0.5H2O, indicates that the molecular ring of the guest is perpendicular to the layer of the host. While the lattice expansion (Ad) of 14 A for [Co(Salen)]0.7oMno.65PS3-H2O, suggests that the molecular ring of the guest has a tilted angle between the layer of the host. The results of SQUID measurements of [Fe(Salen)]o.56Mno.72PS3-0.5H2O and [Mn(Salen)]0.26Mno.87PS3-0.5H2O indicate they show bulk spontaneous magnetization below 40 K, while intercalate [Co(Salen)]o.7oMno.65PS3'H2O exhibits paramagnetism. In the whole temperature range of the measurement, no spin crossover behavior is observed for this series of intercalates.In Chapter 4, the intercalation process of 2,2'-bipyridine into layered MnPS3 is studied with powder XRD technology in detail. From the XRD results it is found that the absence or presence of acid greatly influences the existing form and the arranged orientation of the guest. In Series A, only MnPS3 and 2,2'-bipyridi...