We present new stilbazolium salt DSTMS (4‐N,N‐dimethylamino‐4′‐N′‐methyl‐stilbazolium 2,4,6‐trimethylbenzenesulfonate) with both high second‐order nonlinear optical properties and very favorable crystal growth characteristics. We are able to obtain very large area bulk single crystals of more than 3 × 3 × 0.2 cm3 with a high optical quality without using seed crystals by using low‐temperature solution growth. We also demonstrate the growth of single crystalline thin films of DSTMS with an area of up to 6 × 5 mm2 and a thickness between 5–30 μm. Nonlinear optical measurements reveal that DSTMS possesses large nonlinear optical susceptibilities with χ111(2) = (430 ± 40) pm V–1 at 1.9 μm. Highly efficient generation of broadband THz waves with THz electric field strengths of more than 4 kV cm–1 using 160 fs laser pump pulses at a wavelength λ = 1.45 μm and DSTMS crystals has been demonstrated.

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The macrocyclization between buckminsterfullerene, C,,, and bis-malonate derivatives in a double Singe1 reaction provides a versatile and simple method for the preparation ofcovalent bis-adducts of C,, with high regioand diastereoselectivity. A combination of spectral analysis, stereochemical considerations, and X-ray crystallography ( Fig. 2 ) revealed that out of the possible in-in, in-out, and out-out stereoisomers, the reaction of bis-malonates linked by 0-, ni-, or p-xylylene tethers afforded only the out-out ones (Scheme I). In contrast, the use of larger tethers derived from 1,lO-phenanthroline also provided a first example, (*)-19 (Scltemr 2), of an in-out product. Starting from optically pure bis-malonate derivatives, the new bis-functionalization method permitted the diastereoselective preparation of optically active fullerene derivatives (Schemes 4 and 5 ) and, ultimately, the enantioselective preparation (enantiomeric excess ee > 97 YO) of optically active cis-3 bis-adducts whose chirality results exclusively from the addition pattern (Fig. 6). The macrocyclic fixation of a bis-malonate with an optically active, 9,9-spirobi[9H-fluorene]-derived tether to C,, under generation of 24 and ent-24 with an achiral addition pattern (Scheme 4 ) was found to induce dramatic changes in the chiroptical properties of the tether chromophore such as strong enhancement and reversal of sign of the Cotton effects in the circular dichroism (CD) spectra (Figs. 4 and 5). By the same method, the functionalized bis-adducts 50 and 51 (Schemes 10 and If) were prepared as initiator cores for the synthesis of the fullerene dendrimers 62, 63, and 66 (Schemes 12 and 13) by convergent growth. Finally, the new methodology was extended to the regio-and diastereoselective construction of higher cycbpropanated adducts. Starting from mono-adduct 71, a clipping reaction provided exclusively the all-cis-2 tris-adduct (&)-72 (Scheme 14), whereas the similar reaction of bis-adduct 76 afforded the all-cis-2 tetrakis-adduct 77 (Scheme 15). Electrochemical investigations by steady-state voltammetry (Table 2) in CH,CI, ( + 0 . 1~ Bu,NPF,) showed that all macrocyclic bis(niethan0)fullerenes underwent multiple reduction steps, and that regioisomerism was not much influencing the redox potentials. All cis-2 bis-adducts gave an instable dianion which decomposed during the electrochemical reduction. In CH,CI,, the redox potential of the fullerene core in dendrimers 62, 63, and 66 is not affected by differences in size and density of the surrounding poly(ether-amide) dendrons. The all-cis-2 tris-and tetrakis(methano)fullerenes (5)-72 and 77, respectively, are reduced at more negative potential than previously reported all-e tris-and tetrakis-adducts with methano bridges that are also located along an equatorial belt. This indicates a larger perturbation of the original fullerene rr-chromophore and a larger raise in LUMO energy in the former derivatives.') Present address: Groupe des Matkriaux Organiques,

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The reaction of 1,3-diphenylallylethyl carbonate (1) with benzylamine to afford the secondary amine 2 is effectively catalyzed by Pd-complexes containing chiral ferrocenyl pyrazole ligands. The highest enantioselectivity (99% ee) was obtained using ligand 3a, 1-{(S)-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethyl}-3-(1-adamantyl)-1H-pyrazole. Four different cationic Pd-allyl intermediates, 4a, 4c, 4j, and 4k (containing ligands 3a, 3c, 3j, and 3k, respectively), formed during the catalytic reaction were studied in solution by 2D-NMR spectroscopy, with the aim of clarifying configurational aspects. Depending on the size and shape of the substituent in position 3 of the pyrazole ring, it was found that the major diastereoisomeric form of these complexes either adopts an exo- syn-syn (ligands 3a and 3c, 1-{(S)-1-[(R)-2-(diphenylphosphino)ferrocenyl]-ethyl}-3-phenyl-5-methyl-1H-pyrazole) or an exo-syn-anti configuration (ligands 3j, 1-{(S)-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethyl}-3-(9-anthryl)-5-methyl-1H-pyrazole and 3k, 1-{(S)-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethyl}-3-(9-triptycyl)-1H-pyrazole). This analysis allows the site of nucleophilic attack on the allyl ligand to be established unequivocally, i.e., the carbon atom trans to phosphorus. The reasons responsible for this pronounced site-selectivity are discussed. The Pd-allyl complexes [Pd(η3-PhCHCHCHPh)(3c)]PF6, 4c, and [Pd(η3-PhCHCHCHPh)(3k)]PF6, 4k, were characterized by X-ray diffraction. 4c crystallizes with 1 equiv of Et2O in the orthorhombic space group P212121:  a = 13.026(2) Å, b = 14.784(2) Å, c = 25.124(5) Å, Z = 4. Crystals of 4k contain 3 equiv of hexane and 1 equiv of acetone and H2O in the unit cell belonging to the trigonal system, space group P3221:  a = 24.07(3) Å, c = 22.48(3) Å, Z = 6.