Hybrid Organic/Inorganic Complexes Based on Electroactive Tetrathiafulvalene-Functionalized Diphosphanes Tethered to C 3 -Symmetrized Mo 3 Q 4 (Q = S, Se) Clusters (original) (raw)
Related papers
Organometallics, 2010
Sequential treatment of trimethylsilylethynyl-TTF (TTFMe 3) 3a dissolved in methanol with potassium fluoride, the chloro complex Cp*(dppe)FeCl (8; Cp*=η 5-C 5 (CH 3) 5 , dppe=1,2-bis-(diphenylphosphino)ethane) in the presence of ammonium hexafluorophosphate, and finally with KOBu t provided Cp*(dppe)FeCtC-TTFMe 3 (1), which was isolated in 69% yield as an air-and moisture-sensitive orange powder. The X-ray crystal structure, IR, cyclic voltammetry (CV), UV-vis, M€ ossbauer, and DFT data obtained for 1 show that only weak interactions take place between the iron center and the TTFMe 3 core and that the latter acts as a rather poor electron donor visa -vis the organometallic group. When reacted with 1.0 equiv of [(C 5 H 5) 2 Fe][PF 6 ] in tetrahydrofuran (THF) at-60°C, 1 gives the thermally stable radical cation 1[PF 6 ], which was isolated in a pure form as a purple powder (77%). The Fe III derivative was characterized by the same spectroscopic methods as 1 complemented by HRMS and elemental analyses also obtained for neutral 1. All experimental and theoretical data obtained for 1[PF 6 ] indicate that after one-electron oxidation the relaxation of the molecular structure is characterized by an increase of the Fe-C carbon bond order, the localization of the positive charge on the iron nuclei, and the delocalization of the spin density on the whole molecule. In the radical cation, the interaction between the iron center and the TTFMe 3 fragment is much stronger than in the neutral species, and a good electronic communication characterized by a rather large electronic coupling for a class II MV system takes place (H ab = 320 cm-1 determined from the analysis of the NIR spectrum). Furthermore, the dicationic species 1[PF 6 ] 2 was in situ generated and characterized by IR, NIR, and EPR spectroscopies.
Inorganic Chemistry, 2008
The reaction of p-phenylenediamine with excess PCl3 in the presence of pyridine affords p-C6H4[N(PCl2)2]2 (1) in good yield. Fluorination of 1 with SbF3 produces p-C6H4[N(PF2)2]2 (2). The aminotetra(phosphonites), p-C6H4[N{P(OC6H4OMe-o)2}2]2 (3) and p-C6H4[N{P(OMe)2}2]2 (4) have been prepared by reacting 1 with appropriate amount of 2-(methoxy)phenol or methanol, respectively, in presence of triethylamine. The reactions of 3 and 4 with H2O2, elemental sulfur or selenium afforded the tetrachalcogenides, p-C6H4[N{P(O)(OC6H4OMe-o)2}2]2 (5), p-C6H4[N{P(S)(OMe)2}2]2 (6) and p-C6H4[N{P(Se)(OMe)2}2]2 (7) in good yield. Reactions of 3 with [M(COD)Cl2]
Phys. Chem. Chem. Phys., 2005
The radical cation of the redox active ligand 3,4-dimethyl-3 0 ,4 0-bis-(diphenylphosphino)-tetrathiafulvalene (P2) has been chemically and electrochemically generated and studied by EPR spectroscopy. Consistent with DFT calculations, the observed hyperfine structure (septet due to the two methyl groups) indicates a strong delocalization of the unpaired electron on the central S 2 CQCS 2 part of the tetrathiafulvalene (TTF) moiety and zero spin densities on the phosphine groups. In contrast with the ruthenium(0) carbonyl complexes of P2 whose one-electron oxidation directly leads to decomplexation and produces P2 1 , one-electron oxidation of [Fe(P2)(CO) 3 ] gives rise to the metal-centered oxidation species [Fe (I) (P2)(CO) 3 ], characterized by a coupling with two 31 P nuclei and a rather large g-anisotropy. The stability of this complex is however modest and, after some minutes, the species resulting from the scission of a P-Fe bond is detected. Moreover, in presence of free ligand, [Fe (I) (P2)(CO) 3 ] reacts to give the complex [Fe (I) (P2) 2 (CO)] containing two TTF fragments. The two-electron oxidation of [Fe(P2)(CO) 3 ] leads to decomplexation and to the P2 1 spectrum. Besides EPR spectroscopy, cyclic voltammetry as well as FTIR spectroelectrochemistry are used in order to explain the behaviour of [Fe(P2)(CO) 3 ] upon oxidation. This behaviour notably differs from that of the Ru(0) counterpart. This difference is tentatively rationalized on the basis of structural arguments. w Electronic supplementary information (ESI) available: 3D spectroelectrogram of P2. See
Journal of Organometallic Chemistry, 1999
Two µ 3 -η 2 ,η 2 ,η 2 -C 60 complexes, Os 3 (CO) 8 (PPh 3 )(µ 3 -η 2 ,η 2 ,η 2 -C 60 ) (8) and Os 3 (CO) 7 (PMe 3 ) 2 (µ 3η 2 ,η 2 ,η 2 -C 60 ) (9), have been prepared by decarbonylation of Os 3 (CO) 9 (µ 3 -η 2 ,η 2 ,η 2 -C 60 ) (6) with Me 3 NO/MeCN in the presence of phosphine ligands. The molecular structure of 8 has been determined by a single-crystal X-ray diffraction study. The structure of 8 is derived from that of Os 3 (CO) 11 (PPh 3 ) by replacing three axial carbonyl ligands with a µ 3 -face-capping C 6 ring of C 60 . The 13 C NMR spectra (C 60 region) of 6 and Os 3 (CO) 8 (PMe 3 )(µ 3 -η 2 ,η 2 ,η 2 -C 60 ) show 11 sp 2 and 1 sp 3 carbon resonances and 29 sp 2 and 3 sp 3 carbon resonances, respectively, which are consistent with C 3v and C s symmetric nature of the two complexes in solution. Electrochemical properties of 6, 7, and 9 have been studied by cyclic voltammetry (CV) in 1,2-dichlorobenzene (DCB) solutions. The general features of CV curves have revealed four reversible redox couples for 6 and 7 and three for 9 in the DCB potential window. The µ 3 -η 2 ,η 2 ,η 2 -C 60 complexes, 6, 7, and 9, show a remarkable electrochemical stability compared to the known η 2 -C 60 triosmium carbonyl complexes. The CV results suggest that a C 60mediated electron transfer to the triosmium center takes place in 6 and 7, but three successive C 60 -localized reductions occur in 9.
Synthetic Metals, 2005
The HR 2 Si-functionalized tetrathiafulvalene (TTF) ligand TTF(SiR 2 H) 4 (R = Me 2a; R = Ph 2b) have been synthesized and the molecular structure of 2a determined. The reactivity of the four Si-H bonds for oxidative addition reactions has been exploited. Thus, the bimetallic platinum-silicon complex [(PPh 3) 2 Pt{(Me 2 Si) 2 TTF(SiMe 2) 2 }Pt(PPh 3) 2 ] 3 incorporating TTF(SiMe 2 H) 4 as bridging unit has been assembled by oxidative addition across [Pt(PPh 3) 2 (CH 2 CH 2)]. Electrochemical investigations by means of cyclic voltammetry reveals, for the complex 3, a strong cathodic shift of the two redox processes of the TTF core compared with those of 2a.
Inorganic Chemistry, 2003
A series of fluorous derivatives of group 10 complexes MCl 2 (dppe) and [M(dppe) 2 ](BF 4) 2 (M) Ni, Pd or Pt; dppe) 1,2-bis(diphenylphosphino)ethane) and cis-PtCl 2 (PPh 3) 2 was synthesized. The influence of para-(1H,1H,2H,2Hperfluoroalkyl)dimethylsilyl-functionalization of the phosphine phenyl groups of these complexes, as studied by NMR spectroscopy, cyclovoltammetry (CV), XPS analyses, as well as DFT calculations, points to a weak steric and no significant inductive electronic effect. The steric effect is most pronounced for M) Ni and leads in the case of NiCl 2 (1c) (3c) and [Ni(1c) 2 ](BF 4) 2 (7c) (1c) [CH 2 P{C 6 H 4 (SiMe 2 CH 2 CH 2 C 6 F 13)-4} 2 ] 2) to a tetrahedral distortion from the expected square planar geometry. The solubility behavior of NiCl 2 [CH 2 P{C 6 H 4 (SiMe 3-b (CH 2 CH 2 C x F 2x+1) b)-4} 2 ] 2 (3: b) 1−3; x) 6, 8) in THF, toluene, and cC 6 F 11 CF 3 was found to follow the same trends as those observed for the free fluorous ligands 1. A similar correlation between the partition coefficient (P) of complexes 3 and free 1 was observed in fluorous biphasic solvent systems, with a maximum value obtained for 3f (b) 3, x) 6, P) 23 in favor of the fluorous phase).
European Journal of Inorganic Chemistry, 2016
Two new 4,5-bis(2-cyanoethylthio)-4',5'-(4pyridylethylenedithio)tetrathiafulvalene (L 1) and 4,5-bis(2cyanoethylseleno)-4',5'-(4pyridylethylenedithio)tetrathiafulvalene (L 2) ligands have been elaborated and five new coordination complexes of transition metal ions, namely [Mn 2 (hfac) 4 (L 1) 2 ] 2 (1), [Cd(hfac) 2 (L 1) 2 ]2CHCl 3 (2), [Cu(hfac) 2 (L 1) 2 ] (3), [Co(hfac) 2 (L 1) 2 ]2C 6 H 14 (4) and [Mn(hfac) 2 (L 2) 2 ]2C 6 H 14 (5) (hfac-= 1,1,1,5,5,5hexafluoroacetylacetonate), have been characterized by X-ray diffraction on single crystals. Compounds 2-5 have been identified as mononuclear complexes with different crystal packing depending on the nature of the metal centre. On the contrary, the compound 1 was identified as a cyclic tetranuclear complex in which the ligand L 1 coordinates the Mn II ions through two different pyridyl and nitrile functionalizations. The photo-physical properties of the ligands L 1 and L 2 were studied in solution and rationalized with Time-Dependent Density Functional Theory calculations.
Journal of the American Chemical Society, 1987
... _ _. (15) Cowley, AH; Norman, NC; Pakulski, M.; Bricker, DL; Russell, DH J. Am. Chem. Sot. 1985, 107, 8211. (16) Bartlett, R. A,; Dias, H. V. R.; Flynn, KM; Hope, H.; Murray, B.; Olmstead, MM; Power, PP J. Am. Chem. SOC., preceding paper in this . . issue. ...