catena-Poly[[bis­[(dicyanamido)silver(I)](Ag—Ag)]-μ2-4,4′-bipyridine-κ2 N:N′]

In the title compound, [Ag2(C2N3)2(C10H8N2)]n, the Ag atoms, lying on inversion centers, are separated by 3.3226 (12) Å. Each Ag atom is connected by one bridging 4,4′-bipyridine [Ag—N = 2.177 (4)Å] and a terminal dicyanamide [Ag—N = 2.108 (4) Å]. The Ag—Ag interactions play a key role in constructing a unique neutral polymeric chain

catena-Poly[[[(triphenyl­phosphane)copper(I)]-di-μ-iodido-[(triphenyl­phosphane)copper(I)]-μ-[3,6-bis­(4-pyrid­yl)-1,2,4,5-tetra­zine]] acetonitrile disolvate]

The title compound, {[Cu2I2(C12H8N6)(C18H15P)2]·2CH3CN}n, contains centrosymmetric dinuclear Cu2I2(PPh3)2 units bridged by 3,6-bis­(4-pyrid­yl)-1,2,4,5-tetra­zine ligands lying also across crystallographic inversion centers, giving a chain structure in the ab plane. The distorted tetra­hedral CuI atoms in the dinuclear unit are coordinated by two bridging iodide anions, one pyridine N atom from the substituted tetra­zine ligand and one terminal triphenyl­phosphine P-atom donor. The Cu⋯Cu distance is 2.8293 (12) Å, implying a weak Cu⋯Cu inter­action

catena-Poly[[bis­(dimethyl­formamide-κO)cadmium(II)]-di-μ2-dicyanamido-κ4 N 1:N 5]

In the title compound, [Cd(C2N3)2(C3H7NO)2], the Cd2+ ion lies on an inversion center and adopts an octa­hedral coordination geometry, in which four N atoms from four different dicyanamide ligands lie in the equatorial plane and two dimethyl­formamide O atoms occupy the axial positions. The Cd atoms are connected by two dicyanamide ligands, resulting in a neutral chain propagating parallel to [010]

catena-Poly[copper(II)-di-μ-dicyan­amido-μ-1,3-di-4-pyridylpropane]

In the title compound, [Cu(C2N3)2(C13H14N2)]n, the CuII atom, located on an inversion centre, adopts a distorted octa­hedral coordination by six N atoms, two from 1,3-di-4-pyridylpropane and four from dicyanamide ligands, with significantly different Cu—N distances. The metal centres are linked in an unusual triple-bridged mode into chains parallel to [101]

catena-Poly[[tetra­kis­(hexa­methyl­phospho­ramide-κO)bis­(nitrato-κ2 O,O′)lutetium(III)] [silver(I)-di-μ-sulfido-tungstate(VI)-di-μ-sulfido]]

In the title compound, {[Lu(NO3)2(C6H18N3OP)4][AgWS4]}n, hexa­methyl­phospho­ramide (hmp), tetra­thio­tungstate, silver iodide and lutetium nitrate were self-assembled, forming an anionic {[AgWS4]−}n chain extending parallel to [001]. The LuIII atom in the cation is coordinated by eight O atoms from two nitrate groups and four hmp ligands in a distorted square-anti­prismatic geometry. Together with the two nitrate groups, the cation is monovalent, which leads to the anionic chain having a [WS4Ag] repeat unit. The polymeric anionic chain has a distorted linear configuration with W—Ag—W and Ag—W—Ag angles of 161.66 (2) and 153.503 (12)°, respectively. The title complex is isotypic with the Y, Yb, Eu, Nd, La, Dy and Sm analogues

catena-Poly[[tetra­kis­(hexa­methyl­phospho­ramide-κO)bis­(nitrato-κ2 O,O′)dysprosium(III)] [molybdenum(VI)-di-μ-sulfido-silver(I)-di-μ-sulfido]]

Hexamethyl­phospho­ramide (hmp), tetra­thio­molybdate, silver sulfide and dysprosium nitrate were self-assembled to form an anionic [AgMoS4]n n− chain in the title complex, {[Dy(NO3)2(C6H18N3OP)4][AgMoS4]}n. The central Dy atom in the cation is coordinated by eight O atoms from two nitrate and four hmp ligands, resulting in a distorted square-anti­prismatic environment. Together with the two nitrate ligands, the cation is monovalent, which leads to the anionic chain having an [AgMoS4] repeat unit. The polymeric anionic chain, with Mo—Ag—Mo and Ag—Mo—Ag angles of 161.911 (13) and 154.014 (13)°, respectively, presents a distorted linear configuration. The title complex is isostructural with the W analogue

catena-Poly[[tetra­kis(hexa­methyl­phos­pho­ramide-κO)bis­(nitrato-κ2 O,O′)neodymium(III)] [silver(I)-di-μ2-sulfido-tungsten(VI)-di-μ2-sulfido]]

In the title compound, {[Nd(NO3)2(C6H18N3OP)4][AgWS4]}n, the central Nd atom of the monovalent cation is coordinated by eight O atoms from two nitrate and four hexa­methyl­phospho­ramide ligands. The monovalent anion, {[WS4Ag]−}n, forms a polymeric chain in a distorted linear configuration with W—Ag—W and Ag—W—Ag angles of 163.81 (3) and 154.786 (12)°, respectively. Thirteen C and three N atoms are disordered equally over two positions. One C atom is disordered over two positions with site occupancy factors of 0.6 and 0.4

Hexa­kis­(dimethyl sulfoxide-κO)calcium μ6-oxido-dodeca­kis-μ2-oxido-hexa­oxido­hexa­tungstate(VI)

In the title compound, [Ca(C2H6OS)6][W6O19], the cation and anion both have a crystallographically imposed centre of symmetry. The CaII atom in the cation is coordinated by six O atoms from six dimethyl sulfoxide ligands in a distorted octa­hedral geometry. The [W6O19]2− isopolyanion possesses the well-known Lindqvist structure in which each WVI atom is coordinated by four μ2-O, one terminal O and one μ6-O atom

Predictive PDF control in shaping of molecular weight distribution based-on a new modelling Algorithm

The aims of this work are to develop an efficient modeling method for establishing dynamic output probability density function (PDF) models using measurement data and to investigate predictive control strategies for controlling the full shape of output PDF rather than the key moments. Using the rational square-root (RSR) B-spline approximation, a new modeling algorithm is proposed in which the actual weights are used instead of the pseudo weights in the weights dynamic model. This replacement can reduce computational load effectively in data-based modeling of a high-dimensional output PDF model. The use of the actual weights in modeling and control has been verified by stability analysis. A predictive PDF model is then constructed, based on which predictive control algorithms are established with the purpose to drive the output PDF towards the desired target PDF over the control process. An analytical solution is obtained for the non-constrained predictive PDF control. For the constrained predictive control, the optimal solution is achieved via solving a constrained nonlinear optimization problem. The integrated method of data-based modeling and predictive PDF control is applied to closed-loop control of molecular weight distribution (MWD) in an exemplar styrene polymerization process, through which the modeling efficiency and the merits of predictive control over standard PDF control are demonstrated and discussed