Organometallic Oligomers Based on 1,8-Diisocyano-p-menthane (dmb):  Syntheses and Characterization of the {[M(diphos)(dmb)]BF₄}_n and {[Pd₂(diphos)₂(dmb)](ClO₄)₂}_n Materials (M = Cu, Ag; diphos = dppe, dppp)

Abstract

A new strategy to synthesize organometallic oligomers is presented and consists of using the title diisocyanide and chelated metal fragments with bis(diphenylphosphine)alkanes. The title materials are synthesized by reacting the [M(dppe)(BF4)] and [M2(dppp)2](BF4)2 complexes (M = Cu, Ag; dppe = bis(diphenylphosphino)ethane, dppp = bis(diphenylphosphino)propane) with dmb and the Pd2-bonded d9-d9 Pd2(dmb)2Cl2 dimer with dppe or dppp. The model compounds [M(diphos)(CN-t-Bu)2]BF4 (M = Cu, Ag) and [Pd2(diphos)2(CN-t-Bu)2](ClO4)2 (diphos = dppe, dppp) have been prepared and characterized as well for comparison purposes. Three of the model compounds were also characterized by X-ray crystallography to establish the diphosphine chelating behavior. The materials are amorphous and have been characterized from the measurements of the intrinsic viscosity, DSC, TGA, and XRD, as well as their capacity for making stand-alone films. The intrinsic viscosity data indicate that the Cu and Pd2 materials are oligomeric in solution (approximately 8-9 units), while the Ag materials are smaller. For [[Cu(dppe)(dmb)]BF4]n, a glass transition is reproducibly observed at about 82 degrees C (DeltaCp = 0.43 J/(g deg)), which suggests that these materials are polymeric in the solid state. The Cu and Ag species are luminescent in the solid state at room temperature exhibiting lambda(max) and tau(e) (emission lifetime) around 480-550 nm and 18-48 micros, respectively, while the Pd2 species are not luminescent under these conditions. During the course of this study, the unsaturated [M2(dppp)2](BF4)2 starting materials (M = Cu, Ag) were prepared, one of which (M = Ag) was characterized by crystallography. The bridging behavior of the dppp ligand in this case contrasts with the chelating behavior seen for the saturated [Cu(dppp)(CN-t-Bu)2]BF4 complex.

Synthesis, structure and photoluminescence of [Cu(acac)(dppe)]n with novel 1D zigzag chain-like motif

“…The copper(I) ion is tetrahedrally coordinated by two phosphorus atoms from two dppe ligands and two oxygen atoms from one acac moiety. The Cu-P distances in 1 are 2.271(1) and 2.279(1) Å, with a mean value of 2.275(1) Å, comparable with those reported in the references [14,15]. The observed Cu-O acac distances of 2.072(2) and 2.100(2) Å are longer than those Cu-O acac distances (<2.0 Å) found in other copper(I) complexes containing acac ligands, in which the copper metals are coordinated by acac and nondppe ligands [16][17][18][19][20].…”

Small Metal‐Containing Oligomers Using M2(dmpm)x and M2(dmb)y Luminescent Building Blocks (M = Cu, Ag; x = 2, 3; y = 1, 2)

“…There are also some differences in the photophysical data, in particular the emission lifetimes, between the polymers and the corresponding building blocks [here M 4 (dmb) 4 2ϩ (M ϭ Pd, Pt)]. More recently, a new series of amorphous polymeric materials of the type {M(diphos)(dmb) ϩ } n (M ϭ Cu, Ag), [22] {Pd 2 (diphos) 2 (dmb) 2ϩ } n (diphos ϭ dppe, dppp), [22] {Pd 2 (dmb) 2 Cl 2 } n , [23] and {Pd 2 (dmb) 2 (diphosЈ) 2ϩ } n (diphosЈ ϭ dppb, dpppen, dpph) [23] (Scheme 3) were prepared and characterized. It was clearly demonstrated that polymers in the solid state dissociated to give oligomers in solution (8Ϫ16 units).…”

Unusually Large Bite Angle of a Distally Diphosphanylated Calix[4]arene Chelator

“…A survey of the CCDC revealed that in the vast majority of complexes of general formula [Ag(phosphane) 2 ]BF 4 the P-Ag-P angle lies between 150°-180°, regardless of whether an interaction between the silver atom and the BF 4 unit exists or not. [33][34][35][36] The above bite angle of "only" 138.8°is therefore likely to reflect the strain within the calix backbone, which prevents the ligand from reaching a larger bite angle. This strain becomes apparent in the markedly unsymmetrical orientation of the two phenoxy rings bearing the tolyl groups (the dihedral angles of the latter with the calixarene reference plane are 25°and 44°).…”