1-Ethynyl-2,3,4,5-tetramethylruthenocene was prepared by the reaction of 1-formyl-2,3,4,5-tetramethylruthenocene with trimethylsilyldiazomethyllithium and also by the reaction of 1-(2‘,2‘-dichlorovinyl)-2,3,4,5-tetramethylruthenocene, which was obtained from the reaction of 1-formyl-2,3,4,5-tetramethylruthenocene with lithium dichloromethyldiethylphosphonate and tert-butyllithium in good yield. 1-Ethynyl-2,3,4,5-tetramethylruthenocene reacted with RuClP 2L (P 2 = 2 PPh3 or dppe; L = η-C5H5, η-C5Me5, or η5-C9H7) in the presence of NH4PF6 or AgBF4, followed by the column chromatography on deactivated Al2O3, to give Ru(C⋮CRc‘)P 2L in moderate or good yield. Ru(C⋮CRc)P 2(η5-C9H7) and Ru(C⋮CRc*)P 2(η5-C9H7) were similarly prepared (Rc, Rc‘, and Rc* are ruthenocenyl, 2,3,4,5-tetramethylruthenocenyl, and 1‘,2‘,3‘,4‘,5‘-pentamethylruthenocenyl, respectively). The structures of Ru(C⋮CRc‘)(dppe)(PPh3)2(η-C5H5), Ru(C⋮CRc)(dppe)(η5-C9H7), and Ru(C⋮CRc‘)(dppe)(η5-C9H7) were determined by X-ray analysis. Cyclic voltammetry of the acetylide complexes showed two well-separated quasi-reversible waves. Chemical oxidation of ruthenium(II) 2,3,4,5-tetramethylruthenocenylacetylide complexes gave products whose stability was dependent on the ligand on the Ru(II) moiety. The 13C NMR spectrum of the oxidized species isolated as stable crystals confirmed the structural rearrangement of the bridging acetylide ligand to a μ-η6:η1-[(cyclopentadienylidene)ethylidene] ligand. The structure of [(η-C5H5)Ru(μ-η6:η1-C5Me4CC)Ru(dppe)(η5-C5Me5)](BF4)2 was determined by X-ray analysis.

Structural analysis of bis(glycylglycinato)cadmium(II) complexes prepared to adjust the pH to 6 (A) and 9 (C), were studied by X-ray diffraction and high resolution 113Cd and 13C solid state NMR. In order to compare with the structure of A, structural analysis of bis(glycylglycinato)zinc(II) complexes (B) prepared to adjust the pH to 6 was also performed by the same methods. The structure of A was six coordinate; a five-membered chelate ring was formed between the terminal amino-group and the adjacent O (peptide) and the terminal carboxygroups of the dipeptide ligands were involved in Cd binding in the complex. The structure of B was similar to A, indicating that the Cd nucleus was better suited for probing the Zn nucleus-ligand structure. The structure of C was six coordinate; the four terminal carboxygroups (O) and the two terminal aminogroups (N) of the dipeptide ligands were involved in Cd binding in the complex. High-resolution 113Cd and 13C CP/MAS NMR spectra have been measured in order to obtain detailed information about the structures. The 113Cd signal of A showed a low field chemical shift compared with the peak of C. This means that the chelate ring shows decreased shielding. From the 13C spectra of A and C, it was seen that the Cd nucleus of A is bonded to a carbonyl oxygen (peptide) and the terminal carboxyl group of the dipeptide, but that for C is not bonded to a carbonyl oxygen (peptide).

No abstract

The reaction of biruthenocene with excess p-benzoquinone and boron trifluoride-diethyl ether produced the title complex (1) in good yield. Singlecrystal X-ray analysis revealed that 1 is the Rufulvalene complex with the novel coordination mode µ 2 -η 6 :η 6 . The reaction of 1 with BrThe fulvalene (abbreviated as Fv) ligand is interesting because it provides the possibility of the simultaneous coordination of two metals. Thus, many M-Fv complexes have been reported. 1-6 In M-Fv complexes reported to date, two coordination modes have been found; one is the µ 2 -η 5 :η 5 form, which is the most typical, and the other is the µ 2 -η 4 :η 4 form, found in [Fe 2 Fv-(CO) 6 ] 2+ and related cations. 7,8 Here, we report the synthesis and structure of the Ru-Fv complex 1, which contains a third type of coordination mode (µ 2 -η 6 :η 6 ) for the Fv ligand. Reactions of 1 with Br 2 or PPh 3 are also described. 9 When a benzene-hexane solution containing BF 3 ‚ Et 2 O was added to a solution of biruthenocene (abbreviated as RcRc) and p-benzoquinone in benzene, a black precipitate was obtained immediately. 10 Recrystallization of the precipitate from nitromethane-diethyl ether gave well-formed orange-yellow crystals of 1. The 1 H NMR spectrum of 1 in CD 3 NO 2 showed signals assigned to the Cp ligand at δ 5.79 (s) and two triplets due to the Fv ligand at δ 6.82 (t) and 4.96 (t). The signal pattern suggests a symmetric structure for the molecule and is quite different from that of the mixed-valence (Ru II Ru IV ) biruthenocenium cation, formulated as [CpRu IIFvRu IV CpL] 2+ (L ) CH 3 CN, C 2 H 5 CN). 10 The remarkable difference of the chemical shift between the R-and -protons of the Fv ligand suggests that the Fv ligand is coordinated in an unusual manner. The 13 C NMR spectrum of 1 showed four signals at δ 89.7, 95.7, 87.0, and 74.8, which are assigned to the Cp ligand, the Fv ligand, and the ipso carbon of the Fv ligand, respec- † Saitama University.

The oxidation of [1](1,1′)ferroceno[1](1,1′)ruthenocenophane ([1.1]FcRc) and ferrocenylruthenocenylmethane (FcCH2Rc) with bromo- or chlorobis(η5-cyclopentadienyl)ruthenocenium(1+) hexafluorophosphates gave the title compound, [Fe(C5H4CH2C5H4)(C5H4CH+C5H4)Ru]PF6− (1), as an α-carbonium salt and ferrocenylruthenocenylmethylium+ hexafluorophosphate [FeCp(C5H4CH+C5H4)CpRu]PF6− (3), respectively. The crystal of 1 has been found to be triclinic, space group , a = 10.572(9), b = 10.581(3), c = 9.680(5) Å, α = 99.50(3)°, β = 108.14(5)°, γ = 88.30(5)°, Z = 2, and the final R = 0.082 and Rw = 0.094. The distance between the Ru and Fe is 4.507(3) Å; which is much shorter than the value of neutral [1.1]FcRc one (4.792(2) Å). The two C5H4-rings in the Rc moiety are tilted largely (the tilting angle is 10.74°) due to a strong Ru···Cα (α-metylium) interaction. The crystal of 3 has been found to be orthorhombic, space group Pbca, a = 17.062(5), b = 19.172(6), c = 12.580(7) Å, Z = 8, and the final R = 0.067 and Rw = 0.072. The tilting angle of the Rc moiety is 7.98°. The most interesting difference between 1 and 3 is found in the distance between the Ru and Cα atoms; i.e., the distance of 3 (2.43(2) Å, closer to the Ru–C covalent bond) is significantly shorter than the value of 1 (2.51(1) Å, somewhat longer to the covalent bond); therefore, the greater positive –CH+– charge can be stabilized by a delocalization of the charge over the [RuCp(C5H4CH)]+ fragment for 3. However, the –CH+– charge is spread out over [Fe(C5H4CHC5H4)(C5H4CH2C5H4)Ru]+ for 1. Temperature-dependent 57Fe-Mössbauer spectroscopy (areal intensity ratio of ferrocene and ferrocenium) supports above the conclusion.

In order to determine the differences between ligaments and tendons in terms of change in biochemical composition during maturation, the biochemical characteristics of the anterior cruciate ligament and tibialis posterior tendon of swine were studied. The collagen content of the tibialis posterior tendon was found to increase rapidly with growth of the body, reaching a plateau prior to maturation. In contrast, the rate of increase in the anterior cruciate ligament was slow, indicating that maturation of this tissue is delayed. The quantity of glycosaminoglycan in both the anterior cruciate ligament and the tibialis posterior tendon decreased with growth. In mature animals, glycosaminoglycans in the anterior cruciate ligament included chondroitin sulfate, hyaluronic acid, and dermatan sulfate, but only trace amounts of chondroitin sulfate were found in the tibialis posterior tendon. Although the ratio of dermatan sulfate to hyaluronic acid generally increased with growth, this increase was more conspicuous in the tibialis posterior tendon than in the anterior cruciate ligament. The anterior cruciate ligament and tibialis posterior tendon both contained collagen of types I, III, and V. In mature swine, type III was increased in the anterior cruciate ligament but not in the tibialis posterior tendon. These findings demonstrate slower maturation for ligament than for tendon with regard to the changes in biochemical constituents, especially those in collagen type and glycosaminoglycan, during the growth process, and also suggest that the composition of these tissues changes in accordance with their changing functional requirements.

We have developed a real-time THz imaging system based on the two-dimensional (2D) electro-optic (EO) sampling technique. Employing the 2D EO-sampling technique, we can obtain THz images using a CCD camera at a video rate of up to 30 frames per second. A spatial resolution of 1.4 mm was achieved. This resolution was reasonably close to the theoretical limit determined by diffraction. We observed not only static objects but also moving ones. To acquire spectroscopic information, time-domain images were collected. By processing these images on a computer, we can obtain spectroscopic images. Spectroscopy for silicon wafers was demonstrated.

No abstract