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Research has been conducted on the single-molecule magnet. The heat capacities of this magnet have been investigated and measured via the adiabatic calorimetry without the external magnetic field and the results are described.

Research has been conducted on the single-molecule magnet salts. The preparation of these salts has been carried out in investigating the effects of paramagnetic cations on the anionic single-molecule magnets' relaxation behavior and the results are reported.

Research has been conducted on the mixed-valence tetranuclear manganese complexes functioning as single-molecule magnets. The preparation, X-ray structures and physical characterizations of these complexes have been carried out and the results are reported.

The influence of chloroform solvate molecules on the intramolecular electron transfer in (Fe3O O2CCH3 6 py 3)(CHCl3) and (Fe3O O2CCH3 6 4-Me-py 3)(CHCl3) were examined. The results indicated that although the two complexes were isostructural, the effect of chloroform solvate molecules for each differed. The valence-detrapping phase transitions of both complexes at varying temperatures were also studied.

A one-dimensional chain of interconnected single-molecule magnets (SMMs) is obtained that consists of [Mn4(hmp)6](super 4+) units bridged by chloride ions. The magnetization hysteresis loops for the complex are similar to those for an SMM and show significant coercive field and steps at regular magnetic intervals.

The oxovanadium heptagons sandwiched by [beta]-cyclodextrins has displayed stepped magnetization curves, which are characteristic of level crossings of spin sublevels. Doubly degenerate ground Kramers' doublet spilt into two spin states and the splitting energy gaps have depended upon ring distortions.

The synthesis and structural and magnetic characterization of five [Mn.sub.3][Zn.sub.2] heterometallic complexes are described. The results provide insights into the spin-state changes due to cocrystallizing cation and terminal ligand and the origins of ferromagnetic exchange in [Mn.sup.3] triangles with chemically identical magnetic cores.

The [Tb.sup.III]-[Cu.sup.II]-based single-molecule magnet (SMM) and non-SMM were prepared to understand the symmetry of the ligand field in [Tb.sup.III]-[Cu.sup.II] dinuclear systems, which affects the magnetic anisotropy of the [Tb.sup.III] ions and causes a drastic change from easy-axis to easy-plane anisotropy. The findings from the study could be applied to design the magnetic anisotropy of lanthanide ions to yield novel SMM and single-chain magnet families based on highly anisotropic lanthanide ions.

The structural and magnetic properties of a new, related family of heterometallic cubanes are described. The results of in-depth magnetization and high-frequency electron paramagnetic resonance (HFEPR) experiments and the similarities and differences between the S = 9/2 [Mn.sub.4] single molecule magnets (SMMs) and the new S = 5 [Mn.sub.3]Ni SMMs are highlighted.

Five N-aryl-N-pyridylaminoxyls are prepared as new ligands for cobalt-aminoxyl heterospin systems. The trisubstituted complexes have shown single-molecule magnet (SMM) behavior in the crystalline state and have also displayed s imilar d MM behavior in frozen solution.

The synthesis of two new different heterometallic cubane single-molecule magnets is described. The analysis of the magnetization and magnetic field show that both the complexes are single-molecules magnets.

The N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine compound is used for the synthesis of a novel family of new [Mn.sub.12] clusters with tunable oxidation states. The analysis reveals that the spin of the ground state of these clusters increases with the increase in the number of Mn ions.

The synthesis, structure and magnetic properties of a giant heterometallic [Cu.sup.I.sub.4][Cu.sup.II.sub.13][Mn.sup.II.sub.4][Mn.sup.IV.sub.12] cluster are presented. An approach is brought about to generate this cluster which contains an unprecedented adamantine-like [Mn.sub.28] core connected wholly by [Mn.sub.4][O.sub.4] cubane units and exhibits unusual magnetic properties.

The new hexaferrocene complex, [[Fe.sub.3.sup.III.III.III]O[(FeCOO).sub.6][(DMF).sub.3]].Cl[O.sub.4] (DMF = N,N-dimethylformamide), is synthesized and characterized by X-ray diffraction. The cyclic voltammogram of this complex has confirmed its redox activity associated with the presence of ferrocene units, with very small or negligible electronic interactions between them.

The advances made in calorimetric studies of molecule-based magnets are presented, highlighting the role of calorimetric studies and the various practical applications of molecular-based magnets. Focus is laid on the phase transitions occurring under surrounding pressure and also under applied pressure and magnetic field.

A new heterometal single-molecule magnet (SMM) of [Mn(super III)(sub 2)Ni(super II)(sub 2)Cl2(salpa)(sub 2)], which showed a steplike hysteresis loop characteristic of an SMM, is reported. It is found that tridentate Schiff bases and their reduced derivatives are versatile for assembling heterometal ions.

An antiferromagnetic Fe(super III)(sub 6) (S=0) and a mixed-valence Mn(super II)(sub 3)Mn(super III)(sub 4) wheel (S=21/2) is a single-molecule magnet (SMM). A mixed-valence Mn(super II)(super III) SMM and an antiferromagnetic Fe(super III) ring were prepared by using the same ligand and different metal sources.

Modifying their coordination designs can control the magnetic anisotropy of the Ferrous cubes, considered as good single-molecule magnets. The structures and magnetic features of ferrous cubes with two types of linking Schiff base ligands that cause the Jahn-Teller distortion are described.

A cobalt molecule that functions as a single-molecule magnet, [Co4(hmp)(sub 4)(MeOH)(sub 4)CI4], where hmp(super -) is the anion of hydroxymethylpyridine, is reported. Hysteresis was found in the magnetization versus magnetic field response of this single crystal.

Some of the C5H5- and C5Me5-titanium(IV) complexes with the C8H4S8 ligand is prepared and their electrochemistry and spectroscopies are studied. The crystal structure of Ti(C5Me5)(sub 2)(C8H4S8) is clarified to consist of isolated dimerized units of the molecules through some sulfur-sulfur nonbonded contacts.

A new class of tetranuclear manganese single-molecule magnets with the pyridine-2,6-dimethanol monoanionic ligand pdmH(sub -) is reported. These complexes exhibit a frequency-dependent out-of-phase ac magnetic susceptibility signal.

An unusual single-chain magnet (SCM), which is derived from a twisted arrangement of easy-planes of Fe(super II) along the chain axis, is reported and it generates a novel type of one-dimensional Ising system. An alternating Fe(super II) (high-spin)/Fe(super III) (low-spin) mixed valence single-chain magnet is prepared using a complexed ligand.