Membership Rules for a Molecular Box: The Admission Process and Protection Provided to Guest Molecules

Abstract

Molecular containers are the smallest possible agents for sensing, sorting, and sequestering ions and molecules. [1] Molecular cages based on transition-metal vertices often easily self-assemble, and those with inorganic frameworks are of special interest because their rigidity, uncommon in organic ligands, [2][3][4][5] could give rise to high selectivity with respect to guest size.Prussian Blue (PB) and its variants [6][7][8] are insoluble cyanometallate polymers consisting of boxlike subunits that exhibit ion-exchange behavior. We and others have previously described molecular PB analogues with encapsulated cations. [9][10][11][12] Lacking so far, however, are examples of empty (or voided) ionophilic boxes, which could provide insights into the ion-inclusion process, which is fundamentally relevant to the behavior of PB analogues and the design of a new class of ion-sequestering agents. [13] We have previously reported that the cage [Cs&{CpCo (CN (% 135 3 based on internuclear distances). The availability for the first time of an empty ionophilic box enables the study of ion binding with respect to kinetic and

Research Progress of Porous Liquids

“…[22] Copyright (2018), with permission from Nature Publishing Group. [24] Copyright (2003), with permission from Wiley-VCH. quantify and compare the different host-guest interactions.…”

“…reported an empty molecular box [{Cp(Co(CN) 3 } 4 (Cp*Ru) 4 ] (Co 4 Ru 4 , Cp*=C 5 Me 5 , Cp=C 5 H 5 ) based on a cyanogroup‐bridged cage with the aid of a templating ion (Figure 4). [24] Co 4 Ru 4 had a neutral, discrete and rigid metal‐cube structure. The central cavity of Co 4 Ru 4 was capable of accommodating small molecules such as K + , Rb + , Cs + , Tl + , NH 4 + , MeNH 3 + , and N 2 H 5 + .…”

“…2003, Hsu et al reported an empty molecular box [{Cp (Co(CN) 3 } 4 (Cp*Ru) 4 ] (Co 4 Ru 4 , Cp* = C 5 Me 5 , Cp = C 5 H 5 ) based on a cyanogroup-bridged cage with the aid of a templating ion(Figure 4) [24]. Co 4 Ru 4 had a neutral, discrete and rigid metalcube structure.…”

Structural and mechanistic studies on ion insertion into the molecular box {[CpCo(CN)3]4[Cp*Ru]4}

“…Recently, however, we have been able to prepare neutral boxes, the prototype being {[CpCo(CN) 3 ] 4 [Cp*Ru] 4 } (Co 4 Ru 4 ) [8]. This species forms via the EtNH þ 3 -templated reaction of the constituent organometallic building blocks (Eq.…”

The first anion template cubic cyanometallate cage and its 3,5-dimethyltris(pyrazolyl)methane iron(II,III) tricyanide building blocks

“…Polymerization could be thus inhibited, and a family of cages with a box-like architecture results. Some early examples showed that the reaction of fac À LMðCNÞ nÀ 3 with LMðH 2 OÞ mþ 3 or LMðMeCNÞ mþ 3 resulted in cyanometallate boxes, ½M 8 ðCNÞ 12 4ðnÀmþÞ , from the displacement of the labile MeCN or H 2 O ligand [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. As part of our interest in this area, we are focusing on the coordination complexes of iron, which have the same components as classic Prussian blue materials and will offer the potential for comparison with classic Prussian blue materials.…”