New molecular complexes of fullerenes C60 and C70 with tetraphenylporphyrins [M(tpp)] in which M-H2, MnII, CoII, CuII, ZnII and Fe(III)Cl, have been synthesised. Crystal structures of two C60 complexes with H2TPP, which differ only in the number of benzene solvated molecules, and C60 and C70 complexes with [Cu(tpp)] have been studied. The fullerene molecules form a honeycomb motif in H2TPP.2C60. 3C6H6, puckered graphite-like layers in H2TPP.2C60.4C6H6, zigzag chains in [Cu(tpp)].C70.1.5C7H8.0.5C2HCl3 and columns in [Cu(tpp)]2.C60. H2TPP has van der Waals contacts with C60 through nitrogen atoms and phenyl groups. Copper atoms of the [Cu(tpp)] molecules are weakly coordinated with C70, but form no shortened contacts with C60. The formation of molecular complexes with fullerenes affects the ESR spectra of [M(tpp)] (M = Mn, Co and Cu). [Mn(tpp)] in the complex with C70 lowers its spin state from S = 5/2 to S = 1/2, whereas [Co(tpp)] and [Cu(tpp)] change the constants of hyperfine interaction. ESR, IR, UV-visible and X-ray photoelectron spectroscopic data show no noticeable charge transfer from the porphyrinate to the fullerene molecules.
The paper presents data on the synthesis, IR, electronic, X-ray photoelectron, and ESR spectroscopies of fullerene C 60 molecular complexes with various types of donor compounds, namely, substituted tetrathiafulvalenes, aromatic hydrocarbons, diazodithiafulvalene, tetraphenyldipyranylidene, tetrasulfur tetranitride, saturated amines, some metallocenes, and Co(II) and Mn(II) tetraphenylporphyrins. Crystal structures of some of these complexes are discussed. The degree of charge transfer in the complexes is evaluated from the shift of the F 1u (4) C 60 mode in the IR spectra. The factors responsible for the appearance of the symmetry-forbidden C 60 vibrations and the splitting of the absorption bands of C 60 in the complexes are considered. The electronic absorption spectra of some complexes show the decrease of the intensity of electron transitions of C 60 at 420±530 nm and the appearance of new absorption bands attributed to charge transfer from the donor to C 60 . The dependences of the energy of charge transfer in the C 60 complexes on ionisation and redox potentials of substituted tetrathiafulvalenes are derived. Peculiarities of donor±acceptor interaction of donor molecules with the spherical C 60 are considered.{Characteristics of C 60 complexes are available as supplementary data.
The η2 complex of nickel bis(diphenylphosphanyl)propane with fullerene, {Ni(dppp)(η2‐C60)}·(C6H14)0.84·(C6H4Cl2)0.16 (1) (C6H14: hexane, C6H4Cl2: o‐dichlorobenzene), has been obtained by reduction of the Ni(dppp)Cl2 and C60 mixture with sodium fluorenone in o‐dichlorobenzene and slow precipitation of the single crystals by diffusion of hexane. Nickel coordinates to the 6–6 bond of C60 by η2‐coordination to form Ni–C(C60) bonds with a length of 1.948–1.951(2) Å, which are the shortest M–C bonds among known η2 complexes of fullerenes. The 6–6 bond length [1.488(3) Å] where the Ni atom is coordinated is noticeably longer than the average length of other 6–6 bonds in C60 [1.388(2) Å]. Coordination of nickel to C60 results in the splitting of two bands for two IR‐active modes of C60 into three bands, because of the lower symmetry of C60, and a noticeable shift in the F1u(4) mode of C60 to lower frequencies, as a result of π back‐donation. The dark green complex manifests two absorption bands at 664 and 890 nm in the visible range. The complex is EPR silent since only a weak narrow signal with g = 2.0000 and ΔH = 0.17 mT was found in the EPR spectrum of 1 at room temperature, which originates from about 0.1 % of spins of the total amount of C60.
Radical pairs, polarons, and fullerene anion radicals photoinduced by photons with an energy of 1.98−2.73 eV in bulk heterojunctions formed by poly(3-hexylthiophene) (P3HT) and poly(3-dodecylthiophene) (P3DDT) with [6,6]-phenyl C61-butyric acid methyl ester (PCBM) and 2-(azahomo[60]fullereno)-5-nitropyrimidine (AFNP) fullerene derivatives were studied by a direct light-induced electron paramagnetic resonance (LEPR) method in a wide temperature range. LEPR spectra of the polymer/fullerene composites consist of contributions of mobile and trapped charge carriers. Concentration and magnetic resonance parameters of these charge carriers were found to depend on the energy of initiated photons. Spin−lattice and spin−spin relaxation times of polarons and fullerene anion radicals were determined by the steady-state saturation method. The interaction of most charge carriers with the lattice is characterized by monotonic temperature dependence, whereas the spin−lattice relaxation time of fullerene anion radicals trapped in the P3DDT matrix demonstrates sharper temperature dependence. Spin−spin interaction is shown to be nearly temperature independent and to be governed by structural properties of polymer/fullerene composites. Longitudinal diffusion of polarons and pseudorotation of fullerene derivatives was shown to follow the activation Elliot hopping model. The replacement of the P3HT matrix by P3DDT accelerates polaron dynamics and increases its anisotropy. The energetic barrier required for polaron interchain hopping mainly prevails upon that of its intrachain diffusion in all composites except P3DDT/AFNP one. Spin dynamics becomes easier when the PCBM fullerene derivative is replaced by the AFNP one.
Coordination of tin(II) phthalocyanine to transition metal carbonyl clusters in neutral {Sn(II){Pc(2-)}}(0) or radical anion {Sn(II){Pc(•3-)}}(-) states is reported. Direct interaction of Co4(CO)12 with {Sn(II){Pc(2-)}}(0) yields crystalline complex {Co4(CO)11·Sn(II){Pc(2-))} (1)....
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.