Intercalated layered materials comprising an organic dye and inorganic MPS(3) [where M is either the manganese ion (Mn(2+)) or the cadmium ion (Cd(2+))] phases have been prepared. The intercalation process induces a spontaneous poling, giving rise to an efficiency of 750 times that of urea in second-harmonic generation for the cadmium derivative. In addition, the manganese derivative displays a permanent magnetization below 40 kelvin. Thus, these materials exhibit both a large optical nonlinearity and magnetic ordering.

A series of 35 layered compounds A[M II Cr III (C 2 O 4 ) 3 ]‚n solvent has been synthesized with five different metals (M ) Mn, Fe, Co, Ni, Cu) and seven hyperpolarizable stilbazolium-shaped A chromophores: (4-[4-(dimethylamino)-R-styryl]-N-alkylpyridinium), alkyl ) methyl, ethyl, isopropyl (DAMS, DAES, DAPS respectively); (4-[4-methoxy-R-styryl]-N-alkylpyridinium), alkyl ) isopentyl, heptyl (MIPS, MHS); DAZOP and CINDAMS are DAMS analogues, where the central [CdC] core has replaced by azo or butadiene cores, respectively)]. These compounds have been designed as possible multiproperty materials associating ferromagnetism and second-order optical nonlinearity. Two-third of these compounds exhibit second harmonic generation (with efficiency up to 100 times that of urea at 1.9 µm), the others being inactive. All of them order ferromagnetically below Curie temperatures that range from 6 to 13 K. The structures of DAPS[Mn II -Cr III (C 2 O 4 ) 3 ].CH 3 CN and MIPS[Mn II Cr III (C 2 O 4 ) 3 ] have been resolved. Both of them belong to the centrosymmetric P2 1 /c space group, which accounts for their NLO inactivity. The long axes of the chromophores in a given layer are parallel, but the dipolar moments are antiparallel. Two successive chromophore layers along the stacking direction have approximately orthogonal orientations, giving rise to a doubling of the c parameter. X-ray powder diffraction shows that the high crystalline compounds of the series possess the same monoclinic unit cell as A[Mn II Cr III (C 2 O 4 ) 3 ] (A ) DAPS, MIPS). A search for structure-property correlation emphasizes the relationship between a short interlayer distance and the alignment of the chromophore dipoles.

The possibility of processing MPS 3 (M ) Mn, Cd) layered materials as thin films capable of intercalating nonlinear optical chomophores is investigated. Two different synthetic routes are presented. The first method (solution approach) involves the coprecipitation of transitionmetal ions Mn 2+ with ligands (P 2 S 6 4-) followed by casting on a glass substrate. Such films have a composition similar to the high-temperature-synthesized MnPS 3 phase but exhibit a much lower crystallinity. However, XRD patterns reveal a preferential orientation of the layers parallel to the support. The second process (solid-state approach) uses the ability of the MPS 3 layered compounds to be exfoliated through the successive intercalations of K + and Li + cations. The resulting compounds of formula M 1-x PS 3 Li 2x ‚nH 2 O (x ) 0.18 for the manganese derivative and 0.16 for the cadmium derivative) readily form highly orientated thin films. Highly transparent thin films were obtained from the CdPS 3 starting material. The lithium intercalate thin films were characterized by thermogravimetric techniques, IR spectroscopy, and X-ray diffraction. Their mechanical stability was found to be slightly better than that of the solution-approach-based thin films. The intercalation of a nonlinear optical chromophore (4-[4-(dimethylamino)-R-styryl]-1-methylpyridinium) was performed in these thin layered films, which were found to be much more reactive that the parent bulk MPS 3 .

No. 2, 84774-74-3; 3, 100700-65-0; 4, 86372-61-4; [Rh3(¿tdpmp) 100700-69-4; [Rh3(M-dpmp)Supplementary Material Available: Listings of hydrogen atom positions, bond lengths, bond angles, anisotropic thermal parameters, and structure factor amplitudes (55 pages). Ordering information is given on any current masthead page.

A number of cationic chromophores derived from the stilbazolium skeleton have been synthesized and inserted into the transparent layered MPS 3 compounds (M ) Mn, Cd, Zn). The NLO properties of the intercalates have been studied. Some of the materials are found to be active for second harmonic generation. UV-visible spectroscopy shows that some of the chromophores, once inserted, undergo strong intermolecular interactions and form J-type aggregates along the inorganic galleries, whereas others do not. Moreover, we have found that only those intercalates which contain aggregates are NLO active. The results allow us to understand, at least partially, why the centrosymmetrical MPS 3 host lattice can yield noncentrosymmetrical intercalates. The host lattice appears not so much to impose specific orientations upon the guest species as to favor chromophore aggregation.

The layered MnPS, reacts with a wide range of 'guest' cations G+, leading to new intercalation compounds of the type Mn,_,

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