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61.
Photocyclization of 1,3-bis[2-(2-naphthyl)vinyl]benzene leads regioselectively to dinaphth[1,2-:2′,1′-]anthracene without the need for a blocking bromine substituent at C-2 in the starting material as assumed previously by other workers. 相似文献
62.
Alvaro Delgadillo Paola Romo AnaMaria Leiva Brbara Loeb 《Helvetica chimica acta》2003,86(6):2110-2120
A series of substituted pyrazino[2,3‐f][1,10]‐phenanthroline (Rppl) ligands (with R=Me, COOH, COOMe) were synthetized (see 1 – 4 in Scheme 1). The ligands can be visualized as formed by a bipyridine and a quinoxaline fragment (see A and B ). Homoleptic [Ru(R1ppl)3](PF6)2 and heteropleptic [Ru(R1ppl){(R2)2bpy}2](PF6)2 (R1=H, Me, COOMe and R2=H, Me) metal complexes 5 – 7 and 8 – 13 , respectively, based on these ligands were also synthesized and characterized by conventional techniques (Schemes 2 and 3, resp.). In the heteroleptic complexes, the R1‐ppl ligand reduces at a less‐negative potential than the bpy ligand, reflecting the acceptor property conferred by the quinoxaline moiety. The potentiality of some of these complexes as solar‐cell dyes is discussed. 相似文献
63.
A 1,2-bis(pyridinium)ethane type axle containing a terpyridine chelate group, when combined with 24-membered crown ethers, forms [2]pseudorotaxanes, the stability of which can be controlled by coordination of metal ions with different geometries. 相似文献
64.
65.
The ligand 2,2′;6′,4″-terpyridine combines a chelating bipyridine group and terminal pyridine donor into a single molecule which is incapable of bonding all three donor N-atoms to a single metal center. Upon chelation to Ag(I), a pro-chiral, building block is produced which can subsequently aggregate by terminal coordination of the pyridine nitrogen. Two forms are possible; a discrete bimetallic complex with a center of symmetry and an infinite helical coordination polymer. Which of these structures occurs is dependent upon the counter anion. 相似文献
66.
Jacques Loeb 《Colloid and polymer science》1908,3(3):113-114
Ohne Zusammenfassung 相似文献
67.
68.
Caputo CB Geier SJ Winkelhaus D Mitzel NW Vukotic VN Loeb SJ Stephan DW 《Dalton transactions (Cambridge, England : 2003)》2012,41(7):2131-2139
The lutidine derivative (2,6-Me(2))(4-Bpin)C(5)H(2)N when combined with B(C(6)F(5))(3) yields a frustrated Lewis pair (FLP) which reacts with H(2) to give the salt [(2,6-Me(2))(4-Bpin)C(5)H(2)NH][HB(C(6)F(5))(3)] (1). Similarly 2,2'-(C(5)H(2)(4,6-Me(2))N)(2) and (4,4'-(C(5)H(2)(4,6-Me(2))N)(2) were also combined with B(C(6)F(5))(3) and exposed to H(2) to give [(2,2'-HN(2,6-Me(2))C(5)H(2)C(5)H(2)(4,6-Me(2))N][HB(C(6)F(5))(3)] (2) and [(4,4'-HN(2,6-Me(2))C(5)H(2)C(5)H(2)(2,6-Me(2))N] [HB(C(6)F(5))(3)] (3), respectively. The mono-pyridine-N-oxide 4,4'-N(2,6-Me(2))C(5)H(2)C(5)H(2)(2,6-Me(2))NO formed the adduct (4,4'-N(2,6-Me(2))C(5)H(2)C(5)H(2)(2,6-Me(2))NO)(B(C(6)F(5))(3)) (4) which reacts further with B(C(6)F(5))(3) and H(2) to give [(4,4'-HN(2,6-Me(2))C(5)H(2)C(5)H(2)(2,6-Me(2))NO)B(C(6)F(5))(3)] [HB(C(6)F(5))(3)] (5). In a related sense, 2-amino-6-CF(3)-C(5)H(3)N reacts with B(C(6)F(5))(3) to give (C(5)H(3)(6-CF(3))NH)(2-NH(B(C(6)F(5))(3))) (6). Similarly, the species, 2-amino-quinoline, 8-amino-quinoline and 2-hydroxy-6-methyl-pyridine were reacted with B(C(6)F(5))(3) to give the products as (C(9)H(6)NH)(2-NHB(C(6)F(5))(3)) (7), (C(9)H(6)N)(8-NH(2)B(C(6)F(5))(3)) (8) and (C(5)H(3)(6-Me)NH)(2-OB(C(6)F(5))(3)) (9), respectively; while 2-amino-6-picoline, 2-amino-6-CF(3)-pyridine, 2-amino-quinoline, 8-amino-quinoline and 2-hydroxy-6-methyl-pyridine react with ClB(C(6)F(5))(2) to give the species (C(5)H(3)(6-R)NH)(2-NH(ClB(C(6)F(5))(2))) (R = Me (10), R = CF(3) (11)) (C(9)H(6)NH)(2-NH(ClB(C(6)F(5))(2))) (12), (C(9)H(6)N)(8-NH(2)ClB(C(6)F(5))(2)) (13) and (C(5)H(3)(6-Me)NH)(2-OClB(C(6)F(5))(2)) (14), respectively. In a similar manner, 2-amino-6-picoline and 2-amino-quinoline react with B(C(6)F(5))(2)H to give (C(5)H(3)(6-Me)NH)(2-NH(HB(C(6)F(5))(2))) (15) and (C(9)H(6)NH)(2-NH(HB(C(6)F(5))(2))) (16). The corresponding reaction of 8-amino-quinoline yields (C(9)H(6)N)(8-NHB(C(6)F(5))(2)) (17). In a similar fashion, reaction of 2-amino-6-CF(3)-pyridine resulted in the formation of (18) formulated as (C(5)H(3)(6-CF(3))N)(2-NH(B(C(6)F(5))(2)). Finally, treatment of 15 with iPrMgCl gave (C(9)H(6)N)(2-NH(B(C(6)F(5))(2))) (19). Crystallographic studies of 1, 2, 4, 6, 7, 10, 11, 12 and 15 are reported. 相似文献
69.
When a star is tidally disrupted by a supermassive black hole (SMBH), the streams of liberated gas form an accretion disk after their return to pericenter. We demonstrate that Lense-Thirring precession in the spacetime around a rotating SMBH can produce significant time evolution of the disk angular momentum vector, due to both the periodic precession of the disk and the nonperiodic, differential precession of the bound debris streams. Jet precession and periodic modulation of disk luminosity are possible consequences. The persistence of the jetted x-ray emission in the Swift J164449.3+573451 flare suggests that the jet axis was aligned with the spin axis of the SMBH during this event. 相似文献
70.
[2]Rotaxanes utilising the 1,2-bis(pyridinium)ethane, 24-crown-8 motif can exist in two distinct co-conformations whose relative abundances are solvent dependent. 相似文献