Robin S. Tanke

Synthesis of isolated silver nanoparticles and their aggregates manipulated by light

Photo-induced synthesis and control over the size and shape of colloidal silver nanoparticles is investigated in contrast to photo-stimulated aggregation of small nanoparticles into large fractal-type structures. The feasibility of light-driven nanoengineering which enables manipulation of the sizes and shapes of the isolated nanoparticles is studied by varying the amount and type of the stabilizing agent and the type of optical irradiation.

Laser-stimulated synthesis of large fractal silver nanoaggregates

A laser-stimulated synthesis of large silver nanoaggregates consisting of hundreds or thousands of nanoparticles is investigated. It is shown that the morphology of the synthesized nanostructures can be controlled with light and monitored via the evolution of the colloid absorption spectra. A method is demonstrated that enables production of a significant number of metal nanoaggregates, which are of paramount importance for the subwavelength concentration of electromagnetic fields and the dramatic enhancement of nanoscale electromagnetically driven processes.

Di­chloro­bis­(tri­phenyl­phosphine oxide)­magnesium

The compound [MgCl2(C18H15OP)2] was inadvertantly crystallized during a reaction involving magnesium germanide. It is isostructural to the Mn, Co, Cu and Zn analogs. Since four-coordinate Mg is rare, its structure is reported here. The Mg atom lies on a twofold axis and is surrounded by two O atoms and two Cl atoms in a distorted tetrahedral coordination geometry.

Controlling Synthesis of Nanostructured Silver Aggregates by Light

The possibilities for control over the size and properties of silver nanoaggregates with incoherent and laser light are investigated. The applications in nanoengineering and for giant enhancement of optical processes at nanoscale are discussed.

1,2-Bis{bis­[4-(trifluoro­meth­yl)phen­yl]phosphino}ethane

Crystals of the title compound, C30H20F12P2 or R 2PCH2CH2PR 2 (R = 4-C6H4CF3), were inadvertently prepared while attempting to recrystallize a crude sample of trans-Re(Cl)(N2)(R 2PCH2CH2PR 2)2 from diethyl ether. The molecule lies on a center of inversion. One of the rings lies approximately in the P—C—C—P plane; the dihedral angle is 174.53°.The other ring is not quite perpendicular; the dihedral angle is 71.1°. The compound is isostructural with the R = Ph, 4-C6H4CH3 and 4-C6H4CH2CH3 analogues. It is well known that the basicity of phosphines and diphosphines can be altered by changing the electron-donating ability of R; however, the structural parameters for the title compound do not significantly differ from those of the aforementioned substituted-phenyl compounds.

Iridium(I), -(III), and -(V) complexes of an O-donor ligand in alkyne hydrosilylation

The O-donor ligand C(Ph2PO)3–(triso) stabilises iridium-(I), -(III), and -(V) species such as [(triso)IrH2(SiMePh2)2]; the complexes catalyse the net anti-addition of silanes to alkynes.