The ability of certain transition metals to mediate the reduction of N2 to NH3 has attracted broad interest in the biological and inorganic chemistry communities. Early transition metals such as Mo and W readily bind N2 and mediate its protonation at one or more N atoms to furnish M(N(x)H(y)) species that can be characterized and, in turn, extrude NH3. By contrast, the direct protonation of Fe-N2 species to Fe(N(x)H(y)) products that can be characterized has been elusive. Herein, we show that addition of acid at low temperature to [(TPB)Fe(N2)][Na(12-crown-4)] results in a new S = 1/2 Fe species. EPR, ENDOR, Mössbauer, and EXAFS analysis, coupled with a DFT study, unequivocally assign this new species as [(TPB)Fe≡N-NH2](+), a doubly protonated hydrazido(2-) complex featuring an Fe-to-N triple bond. This unstable species offers strong evidence that the first steps in Fe-mediated nitrogen reduction by [(TPB)Fe(N2)][Na(12-crown-4)] can proceed along a distal or "Chatt-type" pathway. A brief discussion of whether subsequent catalytic steps may involve early or late stage cleavage of the N-N bond, as would be found in limiting distal or alternating mechanisms, respectively, is also provided.
The ability of certain trann class="Chemical">sitionpan> pan> class="Chemical">metals to mediate the reduction of N2 to NH3 has attracted broad interest in the biological and inorganic chemistry communities. Early transition metals such as Mo and W readily bind N2 and mediate its protonation at one or more N atoms to furnish M(N(x)H(y)) species that can be characterized and, in turn, extrude NH3. By contrast, the direct protonation of Fe-N2 species to Fe(N(x)H(y)) products that can be characterized has been elusive. Herein, we show that addition of acid at low temperature to [(TPB)Fe(N2)][Na(12-crown-4)] results in a new S = 1/2 Fe species. EPR, ENDOR, Mössbauer, and EXAFS analysis, coupled with a DFT study, unequivocally assign this new species as [(TPB)Fe≡N-NH2](+), a doubly protonated hydrazido(2-) complexfeaturing an Fe-to-N triple bond. This unstable species offers strong evidence that the first steps in Fe-mediated nitrogen reduction by [(TPB)Fe(N2)][Na(12-crown-4)] can proceed along a distal or "Chatt-type" pathway. A brief discussion of whether subsequent catalytic steps may involve early or late stage cleavage of the N-N bond, as would be found in limiting distal or alternating mechanisms, respectively, is also provided.
Authors: Oliver Einsle; F Akif Tezcan; Susana L A Andrade; Benedikt Schmid; Mika Yoshida; James B Howard; Douglas C Rees Journal: Science Date: 2002-09-06 Impact factor: 47.728
Authors: Michael P Hendrich; William Gunderson; Rachel K Behan; Michael T Green; Mark P Mehn; Theodore A Betley; Connie C Lu; Jonas C Peters Journal: Proc Natl Acad Sci U S A Date: 2006-11-07 Impact factor: 11.205
Authors: Subramaniam Kuppuswamy; Tamara M Powers; Bruce M Johnson; Mark W Bezpalko; Carl K Brozek; Bruce M Foxman; Louise A Berben; Christine M Thomas Journal: Inorg Chem Date: 2012-12-24 Impact factor: 5.165
Authors: William A Gunderson; Daniel L M Suess; Henry Fong; Xiaoping Wang; Christina M Hoffmann; George E Cutsail; Jonas C Peters; Brian M Hoffman Journal: J Am Chem Soc Date: 2014-10-13 Impact factor: 15.419
Authors: George E Cutsail; Benjamin W Stein; Deepak Subedi; Jeremy M Smith; Martin L Kirk; Brian M Hoffman Journal: J Am Chem Soc Date: 2014-08-19 Impact factor: 15.419
Authors: Sean F McWilliams; Eckhard Bill; Gudrun Lukat-Rodgers; Kenton R Rodgers; Brandon Q Mercado; Patrick L Holland Journal: J Am Chem Soc Date: 2018-06-29 Impact factor: 15.419
Authors: Niklas B Thompson; Paul H Oyala; Hai T Dong; Matthew J Chalkley; Jiyong Zhao; E Ercan Alp; Michael Hu; Nicolai Lehnert; Jonas C Peters Journal: Inorg Chem Date: 2019-02-14 Impact factor: 5.165