A new type of interpenetration involving enmeshed independent square grid sheets. The structure of diaquabis-(4,4′-bipyridine)zinc hexafluorosilicate

Abstract

Zn(4,4'-bipy)2SiF6.2H20 (4,4'-bipy = 4,4'-bipyridine) consists of two perpendicular and equivalent stacks of infinite, essentially square grid [Zn(H20)2(4,4'-bipy)2],,2n+ sheets, which interpenetrate so that any particular sheet has an infinite number of perpendicular ones enmeshed or concatenated with it.

A Molecular Antenna Coordination Polymer from Cadmium(II) and 4,4’-Bipyridine Featuring Three Distinct Polymer Strands in the Crystal

“…The solid-state 13 C NMR spectrum of 1 is shown in Figure 7(a). As expected, the spectrum exhibits three groups of lines, which are assigned according to Osborne [51] (solution NMR) and Braga et al [52] (solid-state NMR).…”

“…PXRD analysis of polycrystalline bulk material indicates that the framework structure of the single-crystal of 1 investigated is representative of the bulk material ( Figure 1). According to 13 C solid-state NMR spectroscopy, there is no solvent ethanol in the structure (see Section 2.3). Most bands in the IR spectrum can be ascribed to vibrations of 4,4'-bipy.…”

“…The experimental conditions for the 113 Cd and 13 C CP MAS NMR spectra were as follows: up to 10 kHz spinning rate, 8 s recycle delay, between 2,000 and 20,000 scans, 4 ms contact time, and 4.3 μs 1 H π/2 pulse. Longer recycle delays were used for recording the 13 C CP/MAS NMR spectra of anhydrous 4,4'-bipy and 4,4'-bipy dihydrate. The 113 Cd MAS NMR spectra were measured using single π/3-pulses (3 μs) with a recycle delay of 30 s (2,000-8,000 scans).…”

“…4,4'-Bipyridine (4,4'-bipy) is a prototypical exo-bidentate, rigid linear bridging ligand and has been widely used in crystal engineering of coordination polymers [12]. It has not only played a crucial role in the advancement of coordination polymers [13] but also in the development of discrete (0D) metallosupramolecular compounds [14]. Scheme 1 depicts the most common topological motifs in 1D and 2D coordination polymers containing 4,4'-bipy as bridging ligand.…”

“…In addition, bulk material of solvent-free 4,4'-bipy and its dihydrate were subjected to 13 C solid-state NMR investigations.…”