TY - JOUR
T1 - Synthesis and Electrochemical Properties of cis- and trans-[Mo2(O2C-Fc)2(DArF)2] (O2C-Fc = Ferrocenecarboxylate; DArF = N,N′-Diarylformamidinate)
AU - Cai, Xu Min
AU - Zimmermann, Teresa K.
AU - Pöthig, Alexander
AU - Kühn, Fritz E.
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/7/6
Y1 - 2015/7/6
N2 - The reaction of cis-[Mo2(O2C-Fc)2(NCCH3)4][BF4]2 (cis-1) with three electronically different N,N′-diarylformamidinate (DArF) ligands [DArF = N,N′-diphenylformamidinate (DPhF), N,N′-di(p-trifluoromethylphenyl)formamidinate (DTfmpF), and N,N′-di(p-anisyl)formamidinate (DAniF)] results in products of the general composition [Mo2(O2C-Fc)2(DArF)2]. Even though the trans-[Mo2(O2C-Fc)2(DArF)2] isomers were originally expected to be the sole products, the corresponding cis-[Mo2(O2C-Fc)2(DArF)2] complexes were isolated as well via crystallization and verified unambiguously by X-ray crystallography. All novel complexes, namely, cis-[Mo2(O2C-Fc)2(DPhF)2] (cis-2a), cis-[Mo2(O2C-Fc)2(DTfmpF)2] (cis-2b), and trans-[Mo2(O2C-Fc)2(DAniF)2] (trans-2c), were studied regarding their electrochemical properties with respect to electrolyte, solvent, and ligand. The electron-donating ligand DArF- enables the oxidation of the [Mo2]4+ unit prior to that of Fc, while the oxidation sequence is reversed when acetonitrile or diphosphine ligands are coordinated instead of formamidinate. In the case of trans-[Mo2(O2C-Fc)2(DAniF)2], interactions were found between the two redox-active ferrocenecarboxylate ligands, with a clear ΔE1/2 value originating from the peak-to-peak separation in DPV of around 100 mV with CH2Cl2 as solvent. Furthermore, the second oxidation of the Mo2-handle [Mo2]5+/[Mo2]6+ was exclusively observed with DAniF- as the ligand. Similar absorption patterns in UV-vis spectra were found within the series 2a-2c, corresponding to similar structural and electronic features of the complexes. (Figure Presented).
AB - The reaction of cis-[Mo2(O2C-Fc)2(NCCH3)4][BF4]2 (cis-1) with three electronically different N,N′-diarylformamidinate (DArF) ligands [DArF = N,N′-diphenylformamidinate (DPhF), N,N′-di(p-trifluoromethylphenyl)formamidinate (DTfmpF), and N,N′-di(p-anisyl)formamidinate (DAniF)] results in products of the general composition [Mo2(O2C-Fc)2(DArF)2]. Even though the trans-[Mo2(O2C-Fc)2(DArF)2] isomers were originally expected to be the sole products, the corresponding cis-[Mo2(O2C-Fc)2(DArF)2] complexes were isolated as well via crystallization and verified unambiguously by X-ray crystallography. All novel complexes, namely, cis-[Mo2(O2C-Fc)2(DPhF)2] (cis-2a), cis-[Mo2(O2C-Fc)2(DTfmpF)2] (cis-2b), and trans-[Mo2(O2C-Fc)2(DAniF)2] (trans-2c), were studied regarding their electrochemical properties with respect to electrolyte, solvent, and ligand. The electron-donating ligand DArF- enables the oxidation of the [Mo2]4+ unit prior to that of Fc, while the oxidation sequence is reversed when acetonitrile or diphosphine ligands are coordinated instead of formamidinate. In the case of trans-[Mo2(O2C-Fc)2(DAniF)2], interactions were found between the two redox-active ferrocenecarboxylate ligands, with a clear ΔE1/2 value originating from the peak-to-peak separation in DPV of around 100 mV with CH2Cl2 as solvent. Furthermore, the second oxidation of the Mo2-handle [Mo2]5+/[Mo2]6+ was exclusively observed with DAniF- as the ligand. Similar absorption patterns in UV-vis spectra were found within the series 2a-2c, corresponding to similar structural and electronic features of the complexes. (Figure Presented).
UR - http://www.scopus.com/inward/record.url?scp=84936106551&partnerID=8YFLogxK
U2 - 10.1021/acs.inorgchem.5b00964
DO - 10.1021/acs.inorgchem.5b00964
M3 - Article
AN - SCOPUS:84936106551
SN - 0020-1669
VL - 54
SP - 6631
EP - 6640
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 13
ER -