One-Dimensional Chain-Type Dicopper Coordination Polymer Linked by 1,4-Di(4-pyridyl)benzene; Synthesis, Crystal Structure, Magnetic Property, and Gas-Adsorption Property

A one-dimensional chain-type dicopper(II) coordination polymer with 1,4-di(4-pyridyl)-benzene (dpybz), [Cu2(O2C-tBu)4(dpybz)] (1), is synthesized and characterized by single crystal X-ray diffraction, infrared spectroscopy, and CHN elemental analysis. Single crystal X-ray diffraction confirms that the one-dimensional chains of 1 are assembled with CH···π interactions at the dpybz moieties to form a brick-like porous network structure. Magnetic susceptibility measurement and broken-symmetry density functional theory (BS-DFT) calculations indicate that (i) antiferromagnetic interactions are present between two copper ions through the bridging carboxylate ligands; the observed exchange integral value (J) of 1 is −175.3 cm−1, which is consistent with the DFT-calculated value for 1 (−174.5 cm−1), and (ii) the magnetic interaction between two Cu2 units through the dpybz ligand is negligible. N2 adsorption measurements indicate that the porous structure of 1 is retained even after evacuation of the guest solvents from the pores of 1, and 1 adsorbs N2 molecules into its pores (the Langmuir surface area of 1 is estimated as 538.0 m2/g)

6-Bromo-2-hydroxypyridinate-bridged Paddlewheel-Type Dirhodium Complex Isomers: Synthesis, Crystal Structures, Electrochemical Properties, and Structure-Dependent Absorption Properties

Two new paddlewheel-type dirhodium (Rh2) complex isomers, formulated as trans-2,2- and 3,1-forms of [Rh2(bhp)4] (bhp = 6-bromo-2-hydroxypyridinate), were obtained by the reaction of 6-bromo-2-hydroxypyridine with [Rh2(O2CCH3)4(H2O)2] and characterized by NMR, ESI-MS, and elemental analyses. Single crystal X-ray diffraction analyses clarified that the crystal structure of trans-2,2-form takes a conventional paddlewheel-type dimer structure with no axial coordination ligands, i.e., trans-2,2-[Rh2(bhp)4], whereas that of the 3,1-form changed significantly depending on the kinds of solvent used for crystallization processes; dimer-of-dimers-type tetrarhodium complex, i.e., 3,1-[Rh2(bhp)4]2, and a conventional paddlewheel-type dimer complex with an axial DMF ligand, i.e., 3,1-[Rh2(bhp)4(DMF)], were observed. The 3,1-form showed unique absorption changes that were not observed in the trans-2,2-form; the trans-2,2-form showed an absorption band at approximately 780 nm both in the solid state and in solution (CH2Cl2 and DMF), whereas the 3,1-form showed a similar absorption band at 783 nm in CH2Cl2 solution, but their corresponding bands were blue-shifted in solid state (655 nm) and in DMF solution (608 nm). The molecular structures and the origin of their unique absorption properties of these Rh2 complexes were investigated using density functional theory (DFT) and time-dependent DFT (TDDFT)

Ferrocene-Bearing Homoleptic and Heteroleptic Paddlewheel-Type Dirhodium Complexes

Two ferrocenecarboxylate (fca)-bridged dirhodium (Rh2) complexes, [Rh2(fca)4] (1) and [Rh2(fca)(piv)3] (2; piv = pivalate), were prepared through the carboxylate-exchange reactions of [Rh2(O2CCH3)4(H2O)2] and [Rh2(piv)4], respectively, with fcaH and characterized by 1H NMR, ESI-TOF-MS, and elemental analyses. Single-crystal X-ray diffraction analyses of [Rh2(fca)4(MeOH)2] (1(MeOH)2) and [Rh2(fca)(piv)3(MeOH)2] (2(MeOH)2), which are recrystallized from MeOH-containing solutions of 1 and 2, revealed that (1) 1(MeOH)2 and 2(MeOH)2 possess homoleptic and heteroleptic paddlewheel-type dinuclear structures, respectively; (2) both complexes have a single Rh–Rh bond (2.3771(3) Å for 1(MeOH)2, 2.3712(3) Å for 2(MeOH)2); and (3) the cyclopentadienyl rings of the fca ligands in 1(MeOH)2 adopt an eclipsed conformation, whereas those in 2(MeOH)2 are approximately 12–14° rotated from the staggered conformation. Density functional theory (DFT) calculations revealed that (1) the electronic configurations of the Rh2 core in 1(MeOH)2 and 2(MeOH)2 are π4σ2δ2π*2δ*2π*2 and π4σ2δ2δ*2π*4, respectively; and (2) the occupied molecular orbitals (MOs) localized on the fca ligands are energetically degenerate and relatively more unstable than those on the Rh2 cores. Absorption features and electrochemical properties of 1 and 2 were investigated in a 9:1 CHCl3-MeOH solution and compared with those of fcaH and [Rh2(piv)4]. Through examining the obtained results in detail using time-dependent DFT (TDDFT) and unrestricted DFT, we found that 1 and 2 exhibit charge transfer excitations between the fca ligands and Rh2 cores, and 1 shows electronic interactions between ferrocene units through the Rh2 core in the electrochemical oxidation process

One-Dimensional Chain-Type Dicopper Coordination Polymer Linked by 1,4-Di(4-pyridyl)benzene; Synthesis, Crystal Structure, Magnetic Property, and Gas-Adsorption Property

A one-dimensional chain-type dicopper(II) coordination polymer with 1,4-di(4-pyridyl)-benzene (dpybz), [Cu2(O2C-tBu)4(dpybz)] (1), is synthesized and characterized by single crystal X-ray diffraction, infrared spectroscopy, and CHN elemental analysis. Single crystal X-ray diffraction confirms that the one-dimensional chains of 1 are assembled with CH···π interactions at the dpybz moieties to form a brick-like porous network structure. Magnetic susceptibility measurement and broken-symmetry density functional theory (BS-DFT) calculations indicate that (i) antiferromagnetic interactions are present between two copper ions through the bridging carboxylate ligands; the observed exchange integral value (J) of 1 is −175.3 cm−1, which is consistent with the DFT-calculated value for 1 (−174.5 cm−1), and (ii) the magnetic interaction between two Cu2 units through the dpybz ligand is negligible. N2 adsorption measurements indicate that the porous structure of 1 is retained even after evacuation of the guest solvents from the pores of 1, and 1 adsorbs N2 molecules into its pores (the Langmuir surface area of 1 is estimated as 538.0 m2/g)

(4,4′-Dimethoxy-2,2′-bipyridine-κ2N,N′)bis[2-(pyridin-2-yl)phenyl-κC1]iridium(III) hexafluoridophosphate unknown solvate

The asymmetric unit of the title complex, [Ir(C11H8N)2(C12H12N2O2)]PF6, comprises a [Ir(ppy)2(diMeO-bpy)]+ cation (Hppy = 2-phenylpyridine and diMeO-bpy = 4,4′-dimethoxy-2,2′-bipyridine) and a PF6− anion. The IrIII atom is coordinated by two anionic ppy− ligands, each coordinating in a C^N cyclometalated mode, and one neutral diMeO-bpy ligand, leading to a distorted octahedral geometry defined by a cis-C2N4 donor set. Intermolecular C—F...H contacts lead to a three-dimensional architecture that define columns parallel to a. Unknown disordered solvent molecules reside in these columns with the electron density being treated with SQUEEZE [Spek (2015). Acta Cryst. C71, 9–18]. The unit-cell data do not reflect the presence of the unresolved solvent

Non-clinical assessment design of autologous chondrocyte implantation products

The aims of this study were to investigate the premarket assessment of autologous chondrocyte implantation (ACI) products especially regarding the non-clinical assessment by surveying the guidelines and review reports of authorized ACI products in detail and to provide information regarding the non-clinical assessment of the safety and efficacy for the future development of regenerative medicine products to design effective premarket assessment. The non-clinical assessment plays a role in justifying the testing of investigational products in humans. Effective non-clinical assessments minimize the risk of clinical trials and achieve prompt product development. In this study, we focused on authorized ACI products that remain in the body of patients for a long time and often contain extrinsic components such as animal tissue-derived collagen. We summarized the details of the characteristics of each ACI product, non-clinical assessment design and related guidelines. To design effective non-clinical assessments, we discussed the evaluation method (particularly the validation of clinical assessment and mechanical property testing), the employed animal models, and the differences in the assessment of the safety and efficacy of the products. Based on these investigations, we provide the details of satisfactory non-clinical assessment of ACI products and indicate the possibility of more effective non-clinical assessment of ACI products and other future regenerative medicine products

Re-examination of regulatory opinions in Europe: possible contribution for the approval of the first gene therapy product Glybera

The first commercially approved human gene therapy in the Western world is Glybera (alipogene tiparvovec), which is an adenoassociated viral vector encoding the lipoprotein lipase gene. Glybera was recommended for marketing authorization by the European Medicines Agency in 2012. The European Medicines Agency had only ever reviewed three marketing authorization applications for gene therapy medicinal products. Unlike in the case of Glybera, the applications of the first two products, Cerepro and Contusugene Ladenovec Gendux/Advexin, both of which were for cancer diseases, were withdrawn. In this report, we studied the European public assessment reports of the three gene therapy products. During the assessment process, Glybera was re-examined and reviewed for a fourth time. We therefore researched the re-examination procedure of the European Union regulatory process. Approximately 25% of the new medicinal products initially given negative opinions from the Committee for Medicinal Products for Human Use were ultimately approved after re-examination from 2009 to 2013. The indications of most medicines were changed during the re-examination procedure, and the products were later approved with a mode of approval. These results suggested that the re-examination system in the European Union contributed to the approval of both several new drugs and the first gene therapy product

Regulatory approval for autologous human cells and tissue products in the United States, the European Union, and Japan

Human cells and tissue products belong to a relatively new class of medical products. Therefore, limited information is available on the classification and premarket evaluation of human cells and tissue products in the United States (US), the European Union (EU), and Japan. In this study, the definition, legislation, and approval system of these products were surveyed. A total of nine autologous human cells and tissue products approved until October 2013 were collected. The definitions of human cells and tissue products were compatible among the US, the EU and Japan. The products were classified as human cells, tissue, and cellular and tissue-based products (HCT/Ps) in the US, advanced therapy medicinal products (ATMPs) in the EU, and cell/tissue-engineered products in Japan. These products were categorized as biologics and medical device in the US and Japan, and drug in the EU. The issuance of new guidance induced regulatory impact for manufacturer, especially in the US. These products are subjected to the accelerated approval of biological product, the humanitarian device exemption approval, the premarket application approval, the biologics license application approval, and new drug application approval with specific targeting of postapproval registry or surveillance. Of nine autologous human cells and tissue products, four products had been evaluated using clinical experiences or open clinical trials with small subjects, although the rests of products had been evaluated using comparative clinical trials with control treatment. Our survey suggests that autologous human cells and tissue products would need postmarket-oriented evaluation rather than premarket-oriented evaluation for doctors and patients