The reaction of [Cp*Fe(η5-P5)] with Cu(I)Cl in solvent mixtures of CH2Cl2/|CH3CN leads to the formation of entirely inorganic fullerene-like molecules of the formula [{Cp*Fe(η5:η1:η1:η1:η1:η1-P5)}12{CuCl}10{Cu2Cl3}5{Cu(CH3CN)2}5] (1) possessing 90 inorganic core atoms. This compound represents a structural motif similar to that of C60: cyclo-P5 rings of [Cp*Fe(η5-P5)] molecules are surrounded by six-membered P4Cu2 rings that result from the coordination of each of the phosphorus lone pairs to CuCl metal centers, which are further coordinated by P atoms of other cyclo-P5 rings. Thus, five-and six-membered rings alternate in a manner comparable to that observed in the fullerene molecules. The so-formed half shells are joined by [Cu2Cl3]-as well as by [Cu(CH3CN)2]+ units. The spherical body has an inside diameter of 1.25 nanometers and an outside diameter of 2.13 nanometers, which is about three times as large as that of C60.

Common approaches in the field of self-organization of discrete supramolecular[1] aggregates, networks, and coordination polymers[2] make use of N-donor containing ligands and N-heterocycles to connect different metal centers together. In contrast, however, our goal in this field has been the use of Pn-ligand complexes as linking moieties between metal cations to form well-oriented assemblies as well as onedimensional (1D) and two-dimensional (2D) polymers. The coordination chemistryof Pn-ligand complexes[3] towards cationic metal centers (excluding cationic organometallic complex moieties[4]) has so far been limited to the use of cyclo-P3-ligand complexes, such as [(triphos)M(3-P3)](M Co, Rh, or Ir; triphos 1,1,1-tris(diphenylphosphanylmethyl) ethane), which usually form metal-bridged dimers.[5] In the reactions of the Co complex with CuBr, a multidecker Co complex containing a (CuBr)6 middle deck was obtained,[6] whereas for the Ir complex, the cationic product [{(triphos)IrP3}3Cu5Br4] was formed.[7] However, recentlywe were able to show that [{CpMo- (CO)2}2(, 2-P2)] (Cp C5H5) can be used as a building block to connect CuI and AgI centers to form 1D polymers such as the complexes 1 and 2.[8] Further, we have tried to incorporate compound 3 (Cp* C5Me5)[9] into these investigations. In the past few years, the reaction behavior of 3 has been intensivelyexamined by the group of O. J. Scherer.[3f]

We report the observation of optical-limiting effects in benzene solutions of two neutral nickel complexes with multi-sulfur 1,2 dithiolene ligands, [Ni(medt)2] 1 (medt D 5,6-dihydro-6-methyl-1,4-dithiin-2,3-dithiolate) and [Ni(phdt)2] 2 (phdt D 5,6-dihydro-5-phenyl-1,4-dithiin-2, 3-dithiolate). The limiting effects were observed with nanosecond and picosecond laser pulses. The limiting thresholds of complexes 1 and 2 were≈0:3J/cm2, measured with the ps laser pulses at 532 nm. The linear absorption spectra of the two complexes indicated that their limiting response should cover the visible and near-infrared region (up to 900 nm). Both ps time-resolved pump-probe and Z-scan experiments revealed that the limiting effects should originate from excited-state absorption and refraction superconductors [16-20]. To our best knowledge, no investigations have been carried out on the optical-limiting properties of dithiolene complexes. Here we report the observation of optical-limiting effects in two neutral nickel complexes with multi-sulfur dithiolene ligands, [Ni(medt)2](medt D 5,6-dihydro-6-methyl-1,4-dithiin-2,3-dithiolate)1 and TNi(phdt)2U (phdt D 5,6-dihydro-5-phenyl-1,4-dithinn-2,3-dithiolate) 2. The observation has been carried out by ns and ps laser pulses at a wavelength of 532 nm. The mechanisms leading to the observed limiting effects have also been investigated.

Two new nickel complexes containing strongly bound multi-sulfur 1,2-dithiolene ligands, [NBu4][Ni(bddt)2] 1 and [Ni(bddt)2] 2 (bddt=4a,5,6,7,8,8a-hexahydro-1,4-benzodithiin-2,3-dithiolate), have been synthesized and characterized by electrochemical measurements, IR and UV-VIS-NIR spectroscopies. The optical limiting properties of these nickel complexes have been determined with 32 ps laser pulses of 532 nm wavelength. The limiting thresholds of 1 and 2 are ca. 0.6 and 0.7 Jcm-2, respectively, which are comparable to that observed in C60. Such results show that the nickel dithiolene complexes may be new candidates for optical limiting applications. In addition, the neutral complex [Ni(bddt)2] 2, which shows remarkable absorption in the near-IR region (ε=63000dm3 mol-1cm-1 at 1035nm) and is an excellent candidate as a near-IR dye for Q-switching neodymium lasers, has been additionally characterized by X-ray diffraction.

reaction of the complex [{CpMo(CO)2}2(μ,η2-P2)] (1) with CuI halides leads to the quantitative formation of the novel one-dimensional linear polymers [CuX{Cp2Mo2(-CO)4(μ,η2:η1:η1-P2)}]∞ (X=Cl (4), Br (5), I (6)). The same products 4 and 5 were obtained when 1 was treated with CuCl2 and CuBr2, respectively. The solid-state structures are compared and their remarkable influence on the respective 31P-magic angle spinning (MAS) NMR spectra is interpreted with the help of density functional theory (DFT) calculations on the model compounds [{(CuX)2{Cp2Cr2(-CO)4(μ,η2:η1:η1-P2)}2}3] (X=Cl (4a), Br (5a)) in which the molybdenum atoms are replaced by their lighter homologue chromium.