Encapsulation of an optically nonlinear octupolar guanidinium cation in a host polyanionic Lmonohydrogentartrate lattice leads to a noncentrosymmetric orthorhombic P2~2121 guest-host crystalline structure with cell parameters a = 11.347 (2), b = 11.162(2), c=6.668(2) 1k with Z=4. Final R = 0.049 from 1229 independent reflections. The packing shows strong interlocking between the anionic and cationic sublattices by a multidirectional hydrogen-bonding network. The optimally oriented octupolar crystalline structure for the 222 crystal point group is defined and the corresponding reference maximal nonlinear susceptibility is compared to that of the present guanidinium crystal structure thus pointing out possible improvements via appropriate structural modifications.

We report the synthesis of Co and Fe nanowires and nanotubes electrochemically deposited through nanoporous membranes. Depending upon the pulse electrodeposition parameters, the structure of Co nanowires is either a pure hexagonal phase or a polytype structure related to the stacking of hexagonal and face-centered cubic forms. Similarly, iron nanowires can be prepared with single or multicrystallographic phases. The control of the wire structure was achieved via the overpotential used to initiate growth. Moreover, nanotubes, whose formation could result from a complexation between metal ions and the polymeric membrane, were also directly synthesized.

In Table 1, the room-temperature lifetimes for [ C u ( d ~p ) ~] + and [Cu(tpp)2]+ are incorrect and should be 240 and 190 ns, respectively. The quantum yields are also incorrect and should be as follows: [ C ~( d m p ) ~] + 2.1 x [ C ~( d p p ) ~] + 8.0 x [Cu(bcp)J+ 2.5 X and [ C ~( t p p ) ~] + 10.0 x

The engineering of a new class of organo-mineral salts, where the nonlinear optical (NLO) properties mainly originate from the organic species ['] while the mineral anion provides structural cohesion compared to van der Waals or even hydrogen-bonded organic molecular crystals, has recently been proposed.['] 2-Amino-5-nitropyridinium dihydrogenmonophospate (2ASNPDP) [', exemplifies this strategy and has been shown to exhibit high, but still not fully optimized second harmonic generation tensor coefficients of the order of 10 pm/V. This value results from the hyperpolarizability of the 2-amino-5-nitropyridine (2ASNP) molecules and their favorable herringbone packing with respect to the two-fold axis of the Pna2, orthorhombic structure.Here, we report another favorable case whereby the 2A5NP molecules are encapsulated in tartrate anionic chains. Although tartrate is not a mineral anion in the strict sense, the resulting 2-amino-5-1iitropyridinium-~-monohydrogentartrate (2A5NPLT) may be considered as belonging to the same class of materials as the previously reported 2A5NPDP in view of the close-packed polyanionic framework hosting the NLO-active organic 2ASNP moieties.Our specific interest in 2A5NP is based on: -Its high molecular hyperpolarizability and its relation to the prototype so-called "molecular diode" para-nitroaniline molecule['"1 which has a measured value of the order of 20 x 1 OW3' e.s.u. at the fundamental wavelength of 1.34 pm.133 -The presence of at least three hydrogen bonding sites owing to the amino group and the easily protonated nitrogen atom which provide strong anchoring to the counter anions.-The blue-shifted absorption relative to p-nitroaniline-like resulting from a heteroatom in the ci position with respect to the amino group, suggesting applications in blue light second-harmonic generation.['b1 -The availability of structures for many crystalline 2ASNP