| Molecular magnetic materials have very important application value in information storage and quantum computing of high-performance quantum computers due to their extremely high information storage density.At the same time,molecular magnetic materials,as so-called"grey zone"probes between quantum mechanics and classical mechanics,have attracted extensive attention from scientists in the three fields of physics,chemistry and materials science.The main purpose of this paper is to study the complexes obtained by N-containing ligands and paramagnetic spin carriers in different systems,and explore the synthesis conditions of functional complexes containing N ligands with different structures.In this thesis,we systematically study the structure-magnetism correlation of N-containing complexes in order to obtain molecular magnetic materials with excellent properties.The main research contents are as follows:1. The Fe???spin crossover?SCO?complexs were studied,including the first non-Huffman-type three-dimensional spin crossover coordination polymer based on[Hg?S/Se CN?4]2-building block?1,2?and one-dimensional spin crossover coordination polymer based on DPIP of V-shaped amide bidentate pyridine ligand?3,4?.It were characterized by elemental analysis,infrared spectroscopy,single crystal X-ray diffraction,and the structure-magnetism correlation of this N-containing complexs were systematically studied.For 1,the ligand field is close to the crossing point but 1 remains paramagnetic over all temperatures.In contrast,for 2 the complex undergoes complete thermal induced SCO behaviour centred at T1/2=107.8 K and complete photoconversion of the low spin state into a metastable high-spin state?LIESST?with TLIESST=66.7 K.The current results provide a new route for the design and synthesis of new SCO functional materials with non-Hoffmann-type structures.For 4,complex undergoes a complete thermally induced spin crossover behavior centered at T1/2=120 K with ca.5 K thermal hysteresis loop and light-induced excited spin state trapping effect with TLIESST=65 K.However,either the homologous 3 or the desolvated form of complex 4*is high spin at all temperatures,proving further the concerted synergy for the SCO of 4 between the intrinsic ligand field and that indirectly induced via hydrogen bond interaction.The current results provide valuable information for the design of new 1D SCO systems via the rational control of the cooperated effects derived from the intramolecular coordination bond and the intermolecular supramolecular interactions.2. Dicyanide bridged magnetic complexes are studied by self-assembling trans-[Ru?Salen??CN?2]-,trans-[Fe/Co/Cr?bpb/bpmb/bp Clb??CN?2]-anions and manganese or copper complexes cation.A series of nine new cyanide-bridged heterometallic complexes including two Ru?-Mn? complexes 5,6,one Fe?-Mn? complex 7,two Fe?-Cu? complexes8,10,and four Cr?-Cu? complexes 9,11-13.A pair of cyanide-bridged 4d-3d heterobimetallic chiral macrocyclic enantiomeric magnetic complexes have been successfully assembled from the trans-dicyanoruthenium???building block and chiral Schiff-Base Manganese???building block with the great help of the dihydrogen bond interaction.This is the first cyanide-bridged 4d-3d nano-sized chiral dodeca-metallic magnetic macrocycle containing only the alternative low spin Ru???ion and the high spin Mn???ion.A detailed magnetism study on the chiral macrocyclic complex 5,revealing the single molecular magnet?SMM?characteristic and the magnetic coupling nature between the Ru???and Mn???ion,as well as the magneto-structural correlation,which can provide valuable information for the rational design of single-molecule magnets by controlling both the nature of the magnetic couplings and the spin ground state.The Fe?-Mn? complex 7 is a cationic chain with alternating cyanide-bridged Fe?-Mn? units,which can form a two-dimensional supramolecular structure through the?-?interactions between bipyridine ligands.Investigation of the magnetic properties of Fe?-Mn? complex reveals an antiferromagnetic coupling between the cyanide-bridged Fe? and Mn? ions.The complexes8-10 containing the M2Cu?M=Fe,Cr?core have neutral trinuclear sandwich-like structures.The investigation of their magnetic properties reveals the antiferromagneitic and ferromagnetic coupling between the cyanide-bridged Fe?-Cu? and Cr?-Cu? ions,respectively.Two binuclear Cr?-Cu? complexes 11 and 12 are a chiral enantiomer.Investigation of the magnetic properties of the Cr?-Cu? complexes 11-13 reveals the weak ferromagnetic coupling between the neighboring Cr? and Cu? ions through the bridging cyanide group.3. Multi-cyanide bridged magnetic complexes are studied by self-assembling mer-[Fe?qxcq??CN?3]-,[M?CN?8]3-anions and Schiff-base manganese cation.A series of six new cyanide-bridged heterometallic complexes including four Fe?-Mn? complexes and two Mo/W-Mn? complexes.Four cyanide-bridged Fe?-Mn? complexes 15-18 were prepared by assembling a new structurally characterized mer-tricyanoiron???molecular precursor 14and the corresponding manganese???Schiff-base compound.There are two dimeric binuclear complexes 15,16 and two one-dimensional complexes 17,18.The magnetic property has been experimentally studied and theoretically fitted over the four Fe?-Mn?complexes,revealing the antiferromagnetic interaction in complexes 15,17 and the unusual ferromagnetic coupling in complexes 16,18 between the Fe? ion and the Mn? ion bridged by the cyanide group.Furthermore,the different magnetic coupling nature has been analyzed on the basis of the magneto-structure correlation of the mer-tricyanometallate-based Fe?-Mn? magnetic system.Two Mo/W-Mn? complexes were obtained by self-assembling octacyanate precursor[M?CN?8]3-?M=Mo or W?and the same Schiff-base manganese???.The Mo-Mn? complex 19 shows that it has a cyanide-bridged cationic hexanuclear Mn5Mo structure,while the W-Mn? complex 20 has a cationic binuclear Mn W structure.Investigation of the magnetic properties of Mo/W-Mn? complexes reveals antiferromagnetic interactions within the cyanide-bridged Mn-Mo/W units. |
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