Activation of amide nitrogen-hydrogen bonds by iron and ruthenium phosphine complexes

Excited state properties of mononuclear and binuclear rhenium(I) complexes

“…The emission lifetimes of the phenanthroline complexes are considerably longer than those that have been reported for structurally similar bpy derivatives and increase dramatically with increasing electron donation from methyl substituents. In fact, the lifetime of [(CO)3 (3,4,7,Re(4,4'-bpy)]+ reaches the remarkable value of 15 us in room temperature CH3CN, over 60 times longer than that of the analogous bpy complex.910•14 These results are qualitatively expected from consideration of the energy gap law, which has already been shown to be operative in a series of closely related rhenium complexes.12 On the other hand, the binuclear complexes (with the exception of [(5-Cl-phen)(CO)3Re(4,4'-bpy)Re(CO)3(5-Cl-phen)]2+) exhibit significantly different behavior than their mononuclear counterparts, and a comparison of TA spectra suggests that the underlying reason for such differences is a change in the nature of the lowest lying excited state. Rather than the single 410-450-nm band, which is characteristic of a Re -LL MLCT state, the TA (14) (a) Kober, E.; Meyer, T. J. Inorg.…”

Iron Dihydride Complexes: Synthesis, Reactivity, and Catalytic Applications

“…While NaBH 4 may be used as the hydride source for the synthesis of other iron dihydride complexes, its reaction with trans ‐(dmpe) 2 FeCl 2 (in THF/isopropanol) led to trans ‐(dmpe) 2 FeH(BH 4 ), which was also generated by mixing cis ‐(dmpe) 2 FeH 2 with BH 3 ⋅ THF . For methods that avoid the use of LiAlH 4 , cis ‐(dmpe) 2 FeH 2 could be prepared from Fe(C 8 H 8 ) 2 and dmpe at 150 °C under 100 atm of dihydrogen pressure, through hydrogenolysis of (dmpe) 2 FeH(2‐Np) (Np=naphthyl), via the reduction of trans ‐(dmpe) 2 FeCl 2 by sodium in liquid NH 3 , or from the reaction between trans ‐(dmpe) 2 FeCl 2 and LiBEt 3 H …”

“…Photolysis of cis ‐(dmpe) 2 FeH 2 with CHCl=CCl 2 , CHCl=CHCl ( cis or trans ), or CHCl=CH 2 resulted in dehalogenation of the chlorinated ethylene while forming several iron‐containing products . Reactions of primary amides such as HCO 2 NH 2 , CF 3 CONH 2 , CF 2 HCO 2 NH 2 , and C 6 F 5 CONH 2 gave trans ‐(dmpe) 2 Fe(H)(NHCOR′) as a result of oxidative addition of the N−H bond ,. Amines, alcohols, water, and less acidic amides (e. g., CH 3 CONH 2 ), however, did not exhibit the same reaction pattern.…”

Complexes of the platinum metals. Part 43. N,N′-diphenylamidinato derivatives of ruthenium, osmium and iridium

“…Taken together these syntheses involving cleavage of triazene and amidine N-H bonds provide one of the most prolific examples of transition-metal-mediated N-H bondbreaking reactions reported to date. 5 The reactivity patterns displayed by the triazenes and amidines in these syntheses differ in that there is a marked tendency for the latter to promote concomitant carbonyl-abstraction reactions when carbonylfree ruthenium and osmium precursors are employed. Some of the formamidinato complexes described herein have previously been prepared in this laboratory by the 1,2 insertion of carbodiimides RN==C=NR into metal-hydrogen bond^.^.…”