%0 Journal Article %1 Ringenberg.2017 %A Ringenberg, Mark R. %A Wittkamp, Florian %A Apfel, Ulf-Peter %A Kaim, Wolfgang. %D 2017 %J Inorganic Chemistry %K bisphosphine carbonyl configurational ferrocenyl ferrocenylbisphosphine iron iron;crystal isomerization prepn propanebisphosphine propanebisphosphine;iron spectroelectrochem structure tricarbonyl %N 13 %P 7501--7511 %R 10.1021/acs.inorgchem.7b00957 %T Redox Induced Configurational Isomerization of Bisphosphine-Tricarbonyliron(I) Complexes and the Difference a Ferrocene Makes %V 56 %X The tricarbonyliron (TCFe) complexes Fe(CO)3(dppf) and Fe(CO)3(dppp), where dppf = 1,1'-bis(diphenylphosphino)ferrocene and dppp = 1,3-bis(diphenylphosphino)propane, exhibit redox activity that induces configurational isomerization. The presence of the ferrocenyl (Fc) group stabilizes higher oxidized forms of TCFe. Using spectroelectrochem. (IR, UV-visible, Mossbauer, and EPR) and computational anal., the Fc in the backbone of the dppf ligand tends to form a weak dative bond to the electrophilic TCFeI and TCFeII species. The open shell TCFeI intermediate was stabilized by the distribution of spin between the two Fe centers (Fc and TCFe), whereas lacking the Fc moiety resulted in highly reactive TCFeI species. The [Fe(CO)3(dppf)]+ cation adopts two possible configurations, square-pyramidal (without an Fe-Fe interaction) and trigonal-bipyramidal (contg. an Fe-Fe interaction). The two configurations are in equil. with the trigonal-bipyramidal configuration being enthalpically favored (DH = -7 kJ mol-1). There is an entropic penalty (DS = -20 J mol-1) due to tilting of the Cp (cyclopentadienide) rings of the dppf moieties by $\sim$8°. Addnl., the terminal Fe hydride [FeH(CO)3(dppf)]BF4 was formed by protonation with a strong acid (HBF4·Et2O). [on SciFinder(R)]

@article{Ringenberg.2017, abstract = {The tricarbonyliron (TCFe) complexes Fe(CO)3(dppf) and Fe(CO)3(dppp), where dppf = 1,1'-bis(diphenylphosphino)ferrocene and dppp = 1,3-bis(diphenylphosphino)propane, exhibit redox activity that induces configurational isomerization. The presence of the ferrocenyl (Fc) group stabilizes higher oxidized forms of TCFe. Using spectroelectrochem. (IR, UV-visible, Mossbauer, and EPR) and computational anal., the Fc in the backbone of the dppf ligand tends to form a weak dative bond to the electrophilic TCFeI and TCFeII species. The open shell TCFeI intermediate was stabilized by the distribution of spin between the two Fe centers (Fc and TCFe), whereas lacking the Fc moiety resulted in highly reactive TCFeI species. The [Fe(CO)3(dppf)]+ cation adopts two possible configurations, square-pyramidal (without an Fe-Fe interaction) and trigonal-bipyramidal (contg. an Fe-Fe interaction). The two configurations are in equil. with the trigonal-bipyramidal configuration being enthalpically favored (\textgreek{D}H = -7 kJ mol-1). There is an entropic penalty (\textgreek{D}S = -20 J mol-1) due to tilting of the Cp (cyclopentadienide) rings of the dppf moieties by $\sim$8°. Addnl., the terminal Fe hydride [FeH(CO)3(dppf)]BF4 was formed by protonation with a strong acid (HBF4·Et2O). [on SciFinder(R)]}, added-at = {2019-07-15T13:41:23.000+0200}, author = {Ringenberg, Mark R. and Wittkamp, Florian and Apfel, Ulf-Peter and Kaim, Wolfgang.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/24a78fd419823a85c85eaf675e2e6d5aa/b_schwederski}, doi = {10.1021/acs.inorgchem.7b00957}, interhash = {ff373b971e0208f08d0e8655c80c6fd5}, intrahash = {4a78fd419823a85c85eaf675e2e6d5aa}, issn = {0020-1669}, journal = {Inorganic Chemistry}, keywords = {bisphosphine carbonyl configurational ferrocenyl ferrocenylbisphosphine iron iron;crystal isomerization prepn propanebisphosphine propanebisphosphine;iron spectroelectrochem structure tricarbonyl}, number = 13, pages = {7501--7511}, timestamp = {2019-07-15T11:42:10.000+0200}, title = {Redox Induced Configurational Isomerization of Bisphosphine-Tricarbonyliron(I) Complexes and the Difference a Ferrocene Makes}, volume = 56, year = 2017 }