12738-64-6Relevant articles and documents
Sensing of the Induced Helical Chirality by the Chiroptical Response of the Ferrocene Chromophore
?utalo, Petar,Kodrin, Ivan,Nuskol, Marko,Semen?i?, Mojca ?aki?
, (2021/12/27)
The experimental (infrared, nuclear magnetic resonance, circular dichroism) and computational (density functional theory) methods allowed us to demonstrate the potential of the ferrocene chromophore to translate chiral information stored at N-terminally attached l-Ala, and transmitted through achiral (Aib)n sequence (n=1 to 3), into a characteristic signal in circular dichroism spectra near 470 nm. The sufficiently long tetrapeptide forms a robust and highly organized 310 helices capable of perturbing the environment of the highly symmetric ferrocene chromophore in an asymmetric manner. The origin of the sign in the circular dichroism spectra of the ferrocene chromophore (near the 470 nm) strongly correlates with the sign of the dihedral angle χ, accounting for a rotation of a substituent attached to the cyclopentadienyl ring that depends on the helicity of peptide sequence. These observations may help us in the design of future ferrocene-based probes for the assignment of the screw-sense preference of short peptides.
Scalable Synthesis of Functionalized Ferrocenyl Azides and Amines Enabled by Flow Chemistry
Boeser, Lisa,Christmann, Mathias,Hartmayer, Bence,Heretsch, Philipp,Kleoff, Merlin,Sarkar, Biprajit,Schwan, Johannes
supporting information, (2020/02/04)
A scalable access to functionalized ferrocenyl azides has been realized in flow. By halogen-lithium exchange of ferrocenyl halides and trapping with tosyl azide, a variety of functionalized ferrocenyl azides were obtained in high yields. To allow a scalable preparation of these potentially explosive compounds, a flow protocol was developed accelerating the reaction time to minutes and circumventing accumulation of potentially hazardous intermediates. The corresponding ferrocenyl amines were then prepared by a reliable reduction process.
Bis-ferrocenyl-pyridinediimine trinuclear mixed-valent complexes with metal-binding dependent electronic coupling: Synthesis, structures, and redox-spectroscopic characterization
Carter, Cole,Kratish, Yosi,Jurca, Titel,Gao, Yanshan,Marks, Tobin J.
, p. 18715 - 18729 (2020/11/17)
A family of metal dichloride complexes having a bisferrocenyl- substituted pyridinediimine ligand was systematically synthesized ((Fc2PDI)MCl2, M = Mg, Zn, Fe, and Co) and characterized crystallographically, spectroscopically, electrochemically, and computationally. Electronic coupling between the ligand ferrocene units is switched on upon binding to a MCl2 fragment, as evidenced by both sequential oxidation of the ferrocenes in cyclic voltammetry (ΔEox ≈ 200 mV) and by Inter-Valence Charge Transfer electronic excitations in the near IR. Additionally, UV-vis spectra are used to directly observe orbital mixing between the ferrocenyl units and the imine π system since breaking of the orbital symmetry results in allowed transitions (? = 2800 M-1cm-1 vs ? ≈ 200 M-1cm-1 in free ferrocene) as well as broadening and red-shifting of the ferrocenyl transitions-indicating organic character in formerly pure metal-centered transitions. DFT analysis reveals that interaction between the ferrocenes and the MCl2 fragment is small and suggests that communication is mediated by better energy matching between the ferrocene and organic π? orbitals upon coordination, allowing superexchange coupling through the LUMO. Furthermore, single crystal diffraction data obtained from oxidation of one and both ferrocenes show distortions, introducing the empty dxy/dx2-y2 orbitals into the secondary coordination sphere of the MCl2 fragment. Such structural rearrangements are infrequent in ferrocenyl mixedvalent compounds, and implications for catalysis as well as electronic communication are discussed.
