Air-oxidation of Cp'(4)Fe(4)(HCCH)(2) (Cp' = Cp (1a), C(5)H(4)Me (1b)) in an NH(4)PF(6)/CH(3)CN solution afforded the one-electron oxidized clusters [Cp'(4)Fe(4)(HCCH)(2)](PF(6)). Oxidation of 1a with excess AgBF(4) in THF afforded [1a](BF(4)), while that of 1b with excess AgBF(4) gave [1b](BF(4))(2). The X-ray crystal structure analysis of [1a](BF(4)) revealed that the monocationic cluster retains the butterfly-type Fe(4)(mu4-eta(2):eta(2):eta(1):eta(1)-HCCH)(2) framework similar to that of the neutral cluster. The average Fe-Fe bond length is shorter by 0.029 A than that in the neutral cluster. Electrochemical oxidation of 1a and 1b in 0.1 M NH(4)PF(6)/CH(3)CN solution at +0.30 and +0.25 V versus Ag/10 mM AgNO(3), respectively, afforded the two-electron oxidized clusters [1a](PF(6))(2) and [1b](PF(6))(2). The X-ray crystal structure analysis for [1b](BF(4))(2) shows that the butterfly-type cluster core is retained but shrinks more of those of neutral and monocationic clusters. The four Fe-Fe bonds in [1b](BF(4))(2) are unequivalent: one Fe-Fe bond (2.397(1) A) is apparently shorter than the others (2.439(2)-2.461(2) A).

1,2-Bis[(2,4,6-tri-tert-butylphenyl)phosphinidene]cyclobuta[l]phenanthrene (DPCB-phen) as a low-coordinated phosphorus ligand forms the platinum(0) alkyne complexes [Pt(alkyne)(DPCB-phen)] with extended π-conjugated systems. The colors of the complexes are highly dependent on alkyne ligands, showing a marked variation from reddish orange to teal.

Mn-Zn ferrite, Mn1−xZnxFe2O4 nanoparticles encapsulated in amorphous SiO2 were prepared using our original wet chemical method. X-ray diffraction patterns confirmed that the diameters of these particles were within 7–30 nm. Magnetization measurements for various sample compositions revealed that the saturation magnetization (Ms) of 7 nm particles was maximum for the x = 0.2 sample. AC magnetic susceptibility measurements were performed for Mn0.8Zn0.2Fe2O4 (x = 0.2) samples with 13–30 nm particles. The peak of the imaginary part of the magnetic susceptibility χ″ shifted to higher temperatures as the particle size increased. An AC field was found to cause the increase in temperature, with the 18 nm particles exhibiting the highest temperature increase, as expected. In addition, in vitro experiments were carried out to study the hyperthermia effects of Mn1−xZnxFe2O4 (x = 0.2, 18 nm) particles on human cancer cells.

Treatment of the acetylene-coordinated tetrairon cluster, [(eta5-C5H4Me)4Fe4(HCCH)2]+, with N-bromosuccinimide led to stepwise bromination of two acetylene ligands to form [(eta5-C5H4Me)4Fe4(HCCBr)(HCCH)]+, [(eta5-C5H4Me)4Fe4(HCCBr)2]+, [(eta5-C5H4Me)4Fe4(BrCCBr)(HCCBr)]+, and [(eta5-C5H4Me)4Fe4(BrCCBr)2]+. The reactivity of the bromoacetylene fragment in [(eta5-C5H4Me)4Fe4(HCCBr)(HCCH)]+ toward water, pyridine, and ZnMe2 was also investigated.