Di-2-pyridyl ketone complexes of copper(I): efficient photocatalysts for norbornadiene–quadricyclane conversion

Rhenium(I) di- and tri-carbonyl compounds of polypyridyl-like ligands: electrochemical reactions of fac-[Re(CO)3(dpk)Cl] (dpk = di-2-pyridyl ketone) with electrophiles and Group I and II metal ions

“…Metal compounds containing polypyridyl-like ligands of the type (C 5 H 4 N) 2 X (X = π-donor or -acceptor ligand) are of current interest for their rich physicochemical properties, diverse reactivity patterns, and potential applications in many important chemical processes. [1][2][3][4][5][6][7][8][9][10] Our interest in the chemistry of polypyridyl-like compounds such as di-2-pyridyl ketone (dpk) and di-2-pyridylamine (dpa) was aroused because of their ability to undergo a variety of interesting reactions upon binding to transition metals and we were intrigued to explore how variations in the backbone of these ligands affect their reactivity and the physicochemical properties of their compounds compared to those containing 2,2Ј-bipyridine (bipy).…”

“…Such delocalization of electron density provides a span of charged species from a single neutral precursor and a low-energy M→L charge-transfer pathway which are important in electro-and photo-catalysis. 9 The three-co-ordination mode results from a nucleophilic attack at the carbonyl moiety and leads to the loss of π-accepting ability of the ligand and an increase in electron density around the metal centre. 2-5 A variety of transition-metal compounds containing di-2-pyridylamine has been reported and the acidity of the amine group has been utilized to graft some of these compounds into solid supports.…”

Intramolecular Long-Distance Electron Transfer and Triplet Energy Transfer. Photophysical and Photochemical Studies on a Norbornadiene−Steroid−Benzidine System

“…Photosensitized Isomerization of the Norbornadiene to Quadricyclane Group in N − S − B. The photosensitized valence isomerization of norbornadiene to quadricycylane has been the subject of intense experimental and theoretical investigation in view of its significance in solar energy storage and mechanistic interests. ,, The isomerization mechanism involving triplet−triplet energy transfer has been well understood . Furthermore, dimethyl bicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylate is a good electron acceptor and can also undergo isomerization in the presence of a electron donor sensitizer .…”

Reactions of Dipyridylketone With Group 8 Metal Carbonyls in Different Media

“…In the bidentate mode, delocalization of electrons through the pyridine rings and the keto group result in a wide range of charge species from a neutral precursor and a low energy metal to ligand charge transfer (MLCT) all of which are important in electronic transfer processes and catalysis [5]. It has been found that copper(I)-PPh 3 -dpk complexes are efficient photocatalysts for norbornadiene-quadricyclane conversion [6], which is important as a solar energy storage process [7,8]. On the other hand, the metal promoted hydration of dpk has been of interest for some time since the ligand has the ability to undergo a reaction after initial coordination to a transition metal ion [9][10][11][12][13].…”

“…The N,O,N-tridentate binding mode results in the loss of electronic withdrawing properties of the ligand and enhances the electron density around the metal center [5]. Recently, the reaction of molybdenum(0) hexacarbonyl, [Mo(CO) 6 ], with dpk in refluxing toluene lead to the formation of a high-valent molybdenum(VI)-dioxo compound of hydrated di-2-pyridyl ketone, [Mo(O) 2 (-O)( 3 -dpkO,OH)] 2 [21].…”