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In this study, we report two dinuclear Ru(II) complexes C1 and C2 and compare them to their mononuclear analogues Ref1 and Ref2. The dinuclear species exhibit a much stronger absorption, longer excited-state lifetimes and higher luminescence quantum yields than the mononuclear complexes. In addition, C1 and C2 are easier to reduce. An estimation of the driving forces for the electron transfer processes relevant to photocatalytic hydrogen evolution suggests that C1 and Ref2 possess similar activity as photosensitizer (PS). Yet, the improved photophysical properties of C1 make it a more promising candidate for hydrogen evolution. In hydrogen evolution experiments, C1 indeed exhibits increased activity as PS, however, the catalytic system loses its activity after only a few hours. C2 is less active than the mononuclear complexes despite its superior photophysical properties. This observation is attributed to a lack of driving force for the electron transfer towards the catalyst. Further studies of the dinuclear complex C1 show that it is indeed the PS, which decomposes under the catalytic conditions, presumably due to the electron transfer towards the catalyst being the rate-limiting step. [ABSTRACT FROM AUTHOR]

In this study, we investigate the impact of N‐methylation on the electronic and photophysical properties of both homoleptic and heteroleptic Ru(II) bis‐terpyridine complexes based on the recently reported ligand 4'‐(4‐bromophenyl)‐4,4"' : 4",4""‐dipyridinyl‐2,2' : 6',2"‐terpyridine (Bipytpy), with pyridine substituents in the 4‐ and 4"‐position. The first reduction of the methylated complexes takes place at the pyridinium site and is observed as multi‐electron process. Following N‐methylation, the complexes exhibit higher luminescence quantum yields and longer excited‐state lifetimes. Interestingly, the photophysical properties of the heteroleptic and homoleptic complexes are rather similar. TD‐DFT calculations support the experimental results. Furthermore, the complexes are tested as photosensitizers for photocatalytic hydrogen production, as the parent complex 1 [Ru(Bipytpy)(Tolyltpy)](PF6)2 (Tolyltpy: 4′‐tolyl‐2,2′ : 6′,2′'‐terpyridine) was recently shown to be active and highly stable under photocatalytic conditions. However, the methylated complexes reported herein are inactive as photosensitizers under the chosen conditions, presumably due to loss of the methyl groups, converting them to the non‐methylated parent complexes. [ABSTRACT FROM AUTHOR]

Motivated by the recent report of a heteroleptic ruthenium bis-terpyridine complex [Ru(toltpy)(bipytpy)](PF6)2 (toltpy: 4′-(tolyl)-2,2′:6′,2′′-terpyridine; bipytpy: 4′-(4-bromophenyl)-4,4′′′:4′′,4′′′′-di-pyridinyl-2,2′:6′,2′′-terpyridine) capable of driving the photo-evolution of hydrogen with a constant rate of activity for 12 days [M. Rupp et al., Inorg. Chem., 2019, 58, 9127–9134], we investigated the impact of an internal electron donor on the photoactivity of three new ruthenium bis-terpyridine photosensitizers. We used 4′-(N,N-dimethylaminophenyl)-4,4′′-di-tert-butyl-2,2′:6′,2′′-terpyridine (Dtpy) as the donor ligand. These complexes also bear peripheral coordination sites at various positions on the terpyridine backbone, allowing for photosensitizer–catalyst interactions. Their performances in photocatalysis under blue and green light (450 and 525 nm, respectively) were measured, in the presence of triethanolamine, using a cobaloxime catalyst [Co(dmgH)2(H2O)2](BF4)2. Complexes C1[Ru(Dtpy)(pytpy)](PF6)2 (pytpy: 4′-(pyridin-4-yl)-2,2′:6′,2′′-terpyridine) and C3[Ru(Dtpy)(bipytpy)](PF6)2 appeared to have a photostability similar to that of [Ru(toltpy)(bipytpy)](PF6)2 but with lower activity rates, while C2[Ru(Dtpy)(pz2bpy)](PF6)2 (pz2bpy: 2,6-di(pyrazin-2-yl)-4,4′-bipyridine) showed a better peak activity, however, followed by a progressive decay. After 24 hours, complexes C1, C2 and C3 had reached TONs of 18, 35 and 52 under blue light and 14, 20 and 47 under green light, respectively, and were still found to be active. Their photophysical and electronic properties are discussed to rationalize the photocatalytic trends. [ABSTRACT FROM AUTHOR]

The article presents information on the evolution of the journal that was founded by Gérard Parizeau with respect to the insurance and risk management of the companies in Quebec that are emphasised by the journal. The evolution is traced back by five periods of the journal that includes the developing period from 1950 to 1975, the period of HEC Montréal and the period during the ownership of Sodarcan group.

Presents information on Interphase Power Controller technology (IPC), which was developed for the management of power flows within alternating direct networks. Description of technology; Types of IPC; Power characteristics of IPC; Assessment of a simulator demonstration of IPC.

In rat intestine, the 9 kilodalton calbindin (CaBP9K) is significantly increased in vivo by 1,25-dihydroxyvitamin D3 (1, 25(OH)2D3) through a vitamin D (D) response element located in the 5'-flanking region of the gene. However, in vitro calcium has also been reported to increase CaBP9K gene expression in fetal duodenal culture preparations. The aim of the studies was to investigate whether calcium feeding alone can influence CaBP9K gene expression in vivo in adult rat duodena by evaluating the pattern of expression of its mRNA following short- or long-term exposure to oral calcium, comparing the data to exposure to the known inducer of the gene, 1, 25(OH)2D3. Hypocalcemic D-depleted rats were acutely or chronically supplemented with calcium per os, or with 1,25(OH)2D3 in the presence or absence of oral calcium. Short-term calcium feeding was shown to significantly increase the expression of the CaBP9K gene to a level similar to that observed in 1,25(OH)2D3-treated rats but no additive effect between oral calcium and 1,25(OH)2D3 on the level of its mRNA was observed. Moreover, the calcium effect on CaBP9K gene expression was shown to be independent of the circulating ionized calcium concentration and, contrary to the effect of 1,25(OH)2D3, not sustained following long-term exposure. Our data clearly indicate that oral calcium alone has a significant but only transient effect of the expression of the adult rat intestinal CaBP9K gene in vivo and that maintenance of its expression requires normalization of the D endocrine system. [ABSTRACT FROM AUTHOR]

Studies the association between treatment for Hodgkin's disease and the incidence for second cancers. Confirmation on the association of chemotherapy with increased risk of a second cancer; Risk of developing leukemia from cancer treatment; Determination of the risk/balance of treatment.