Role of NEt₄⁺ in Orienting and Locking Together [M₂lig₃]^2– (6,3) Sheets (H₂lig = Chloranilic or Fluoranilic Acid) to Generate Spacious Channels Perpendicular to the Sheets

Abstract

In the presence of the Et 4 N + cation the chloranilate dianion (can 2− ) associates with a range of divalent cations, M 2+ , to yield an isomorphous series of crystalline compounds of composition (Et 4 N) 2 [M 2 (can) 3 ] (M = Mg, Mn, Fe, Co, Ni, Cu, and Zn). The fluoranilate dianion (fan 2− ) likewise affords the closely related (Et 4 N) 2 [Zn 2 (fan) 3 ]. The structures of (Et 4 N) 2 [Zn 2 (can) 3 ], (Et 4 N) 2 [Fe 2 (can) 3 ], and (Et 4 N) 2 [Zn 2 (fan) 3 ] were determined by single crystal X-ray diffraction. Powder X-ray diffraction indicates that all the members of the can 2− series are isomorphous. The structure of (Et 4 N) 2 [Zn 2 (fan) 3 ] is very closely related to the structures of the can 2− compounds. The [M 2 (can) 3 2−

Square Grid Metal–Chloranilate Networks as Robust Host Systems for Guest Sorption

“…[21] Hence it is not clear which mechanism appears likely to apply to (Et 4 N)[Gd III (can) 2 ]b ut other anilate network solids need to be investigated,a long with theoretical (ab initio and DFT) calculations to confirm this andt os ee how widespreads low relaxation is for Gd III species. We have preliminary observations for similarf requency dependentA Cb ehaviour in DC fields for lanthanoid networks such as (NBu 4 ) 2 [Gd 2 (can) 5 (Na(H 2 O) 3 ) 2 ]w ith maximai nc M '' being clearly observed. [22] We also notet hat slow magnetisation relaxation has recently been reported for the 2D transition metal network material(NPr 4 ) 2 [Fe 2 (can) 3 ]·2acetone·H 2 O.…”

“…[3a] Similars tructuralb ehaviour is apparent when related ligands such as chloranilate (I, X = Cl) are employed. [5] In additiont op rovidings trong, predictablel inks between metalc entres, interest in dhbq-type ligandsr elates to the ac-cessibility of multiple oxidation states. The quinonef orm (I)i s capable of undergoing a2 -electron reduction to the aromatic form (III).…”

“…In Figure S6.7, it can be seen that broad, frequencyd ependent maximaa re observed in aD Cf ield of 0.35 Ta t3K( 997 Hz) and 4K (1488 Hz), while frequency dependenttails are observed for lower frequencies.Therei sprecedence for such behaviour in the case of ac hain structure found in the complex Na[Gd(EDTA)(H 2 O) 3 ]·5 H 2 O. [20] The zig-zag chains are made up of doubly water/h 1 -carboxylate bridged -(O) 2 -Gd-(O) 2 -Na-(O) 2 -Gd-moieties with the intramoleculard istance between Gd···Gd ions being 6.0782 (5) .D ipolar Gd···Gd interactions were deemed to be important in the magnetism rather than superexchange interactions. The Gd···Gd separation in the present network is 8.66368 (14) ,a cross the can 2À bridges.T he slow relaxation of magnetisation in the EDTAs pecies, observed in a0 .45 TD Cf ield,w as ascribed to spin phonon transitions between the closely spaced levels (< 1cm À1 )b rought about by spin-orbit splitting of the ground 8 Sg round state, the latter yielding anisotropy.H owever, it has been shown that distortions of the crystal field in polyoxometallate single-ionc ompounds of type [Gd(W 5 O 18 ) 2 ] 9À lead to anisotropy and slow magnetisation relaxation occurring in the milliKelvin range.…”

Two-dimensional, conductive niobium and molybdenum metal–organic frameworks

“…11,38 If metal-to-ligand electron transfers occur exclusively through inner-sphere processes, the use of a trivalent precursor complex should yield charge-neutral frameworks of the general formula M 2 (Cl 2 dhbq) 3 , regardless of the nal redox states of the metals and ligands. Charge-balancing cations in the pores of anionic chloranilate frameworks have been shown to promote ordered interlayer stacking over large length scales, 39 and thus, the absence of charge-balancing cations in 1-Nb and 2-Mo could explain the broad peaks observed in their powder X-ray diffraction patterns. To test for the presence of alkylammonium cations, the frameworks were digested in D 2 O and the resulting solutions were analysed by 1 H NMR spectroscopy (Fig.…”

Quantification of the mixed-valence and intervalence charge transfer properties of a cofacial metal–organic framework via single crystal electronic absorption spectroscopy

“…This through-bond IVCT and associated mixed valency has since been reported in a number of other MOF materials with the relatively high conductivities attributed to the low energy barrier to charge transfer associated with IVCT. 6,11,[26][27][28] An alternative mechanism that facilitates IVCT and has received less attention is the so-called through-space approach where the close cofacial stacking of electroactive units facilitates IVCT between mixed-valence species via orbital overlap. The reported examples exhibit thiazolo [5,4-d]thiazole (TzTz) ligands cofacially stacked in close proximity which, upon either electrochemical or chemical reduction, facilitate IVCT.…”