(+)-{1,2-Bis[(2R,5R)-2,5-dimethyl-phospho-lan-1-yl]ethane- κ2 P,P′}(η4-cyclo-octa-1,5-diene) rhodium(I) tetra-fluorido-borate

The title compound, [Rh(C8H12)(C14H 28P2)]BF4, exhibits a rhodium(I) complex cation with a bidentate bis-phosphine ligand and a bidentate η2, η2-coordinated cyclo-octa-1,5-diene. Together the ligands create a slightly distorted square-planar cordination environment for the Rh(I) atom. There are three mol-ecules in the asymmetric unit and intra-molecular P - Rh - P bite angles of 82.78 (5), 82.97 (6) and 83.09 (5)° are observed. The dihedral angles between the P - Rh - P and the X - Rh - X planes (X is the centroid of a double bond) are 14.7 (1), 14.8 (1) and 15.3 (1)°. The structure exhibits disorder of one cyclo-octa-diene ligand as well as one BF4 anion

Crystal structure of (2,3-bis((2R,5R)-2,5-dimethylphosphonalyl)maleic anhydride)-(η4-norbornadiene)-rhodium(I) tetrafluoroborate, [Rh(C7H8)(C16H24O3P 2)] [BF4]

C23H32BF4O3P2Rh, orthorhombic, P212121 (no. 19), a = 10.147(2) Å, b = 13.246(3) Å, c = 18.827(4) Å, V = 2530.5 Å3, Z = 4, Rgt(F) = 0.025, wRref(F 2) = 0.067, T = 200 K. © by Oldenbourg Wissenschaftsverlag,

Crystal structure of (η4-cycloocta-1,5-dien)-N-(2- (diphenylphosphinooxy)-3-(naphthalen-1-yloxy)propyl)-N-(pentan-3-yl)-1, 1-diphenylphosphinamine-rhodium(I) tetrafluoroborate, [Rh(C8H 12)(C42H43NO2P2)][BF 4]

C50H55BF4NO2P2Rh, monoclinic, P1211 (no. 4), a = 12.722(3) Å, b = 15.248(3) Å, c = 12.818(3) Å, β = 115.80(3)°, V = 2238.7 Å3, Z = 2, Rgt(F) = 0.036, wRref(F 2) = 0.079, T = 200 K. © by Oldenbourg Wissenschaftsverlag

Crystal structure of (η4-cycloocta-1,5-dien)-((+)-1, 1′-bis((2R,4R)-2,4-diethyl-phosphotano)-ferrocene)-rhodium(I) tetrafluoroborate, [Rh(C8H12)Fe(C12H 18FeP)2][BF4]

C32H48BF4FeP2Rh, orthorhombic, P212121 (no. 19), a = 10.640(2) Å, b = 16.007(3) Å, c = 19.460(4) Å, V = 3314.3 Å3, Z = 4, Rgt(F) = 0.044, wRref(F2) = 0.089, T = 200 K. © by Oldenbourg Wissenschaftsverlag

(+)-{1,2-Bis[(2R,5R)-2,5-diethyl-phospho-lan-1-yl]ethane- κ2 P,P′}(≠4-cyclo-octa-1,5-diene)rhodium(I) tetra-fluoridoborate

The title compound, [Rh(C8H12)(C18H 36P2)]BF4, exhibits a rhodium(I) complex cation with a bidentate bis-phosphine ligand and a bidentate 2, 2-coordinated cyclo-octa-1,5-diene ligand. The ligands form a slightly distorted square-planar coordination environment for the Rh(I) atom. An intra-molecular P-Rh-P bite angle of 83.91 (2)° is observed. The dihedral angle between the P - Rh - P and the X - Rh - X planes (X is the centroid of a double bond) is 14.0 (1)°. The BF4 anion is disordered over two positions in a 0.515 (7):0.485 (7) ratio

Crystal structure of (η4-cycloocta-1,5-dien)(1,2-bis(diethylphosphino)-ethane)rhodium(I) tetrafluoroborate, [Rh(C8H12(C10H24P2)]BF4)

C18H36BF4P2RI1, monoclinic, P121/n1 (no. 14), a = 15.522(3) Å, b = 9.173(2) Å, c = 15.862(3) Å, β = 103.91(3)°, V= 2192.3 Å3, Z = 4, Rgt(F) = 0.037, wRref(F2) = 0.087, T=200 K

(+)-Chlorido[(1,2,3,4-η;P 2′)-2′- diphenylphosphanyl-2-diphenylphosphoryl-1,1′-binaphthyl]rhodium(I) methanol monosolvate

In the title complex, [RhCl(C 44H 32OP 2)]·CH 3OH, the Rh I ion is coordinated by a naphthyl group of a partially oxidized 2,2′-bis-(diphenylphosphanyl)-1, 1′-binaphthyl (BINAP) ligand in a 4 mode, one P atom of the diphenylphosphanyl group and one Cl atom. The P=O group does not interact with the Rh I ion but accepts an O - H⋯O hydrogen bond from the methanol solvent molecule

Crystal structure of (η4-norborna-2,5-dien)-(1,2-bis((R,R)-2,5-bis-(methoxymethyl)phospholanyl)benzene)rhodium(I) tetrafluoroborate, [Rh(C22H36O4P2)(C7H8)](BF4)

C29H44BF4O4P2Rh, monoclinic, P21 (no. 4), a= 10.119(2) Å, 6= 14.125(3) Å, c = 11.542(2) Å, β = 106.87(3)°, V = 1578.7 Å3, Z= 2, Rgt(F) = 0.034, wRref(F2) = 0.090, T = 200 K

Fluctuating-friction molecular motors

We show that the correlated stochastic fluctuation of the friction coefficient can give rise to long-range directional motion of a particle undergoing Brownian random walk in a constant periodic energy potential landscape. The occurrence of this motion requires the presence of two additional independent bodies interacting with the particle via friction and via the energy potential, respectively, which can move relative to each other. Such three-body system generalizes the classical Brownian ratchet mechanism, which requires only two interacting bodies. In particular, we describe a simple two-level model of fluctuating-friction molecular motor that can be solved analytically. In our previous work [M.K., L.M and D.P. 2000 J. Nonlinear Opt. Phys. Mater. vol. 9, 157] this model has been first applied to understanding the fundamental mechanism of the photoinduced reorientation of dye-doped liquid crystals. Applications of the same idea to other fields such as molecular biology and nanotechnology can however be envisioned. As an example, in this paper we work out a model of the actomyosin system based on the fluctuating-friction mechanism.Comment: to be published in J. Physics Condensed Matter (http://www.iop.org/Journals/JPhysCM