Discrete Water Hexamers and Template-Assisted Molecular Recognition in an Elastic Zincophosphate Lattice

Abstract

Water molecules and terephthalic acid, respectively, exist as a self-assembled monolayer of cyclic (H2O)6 clusters and (TA)infinity chiral chains between the zincophosphate sheets (in blue wires); the irremovable template H3tren3+ ions (in purple wires) are dynamic and could translate back and forth on the sheets during the conversion of the supramolecule contained in one another.

Co-operation of π⋯π, Cu(II)⋯π, carbonyl⋯π and hydrogen-bonding forces leading to the formation of water cluster mimics observed in the reassessed crystal structure of [Cu(mal)(phen)(H2O)]2·3H2O (H2mal=malonic acid, phen=1,10-phenanthroline)

“…The bond angles in the hexamer mimic vary widely with the average angle being 107.71°, which is interestingly very close to the corresponding value of 109.3°found in hexagonal ice. Hence, the average OÁ Á ÁO distances and angles found in this mimic are similar to those of a regular hexagonal water cluster in chair conformation [69][70][71][72][73][74][75][76][77]. The fact that the cluster mimic is structurally close to a regular water cluster although it is generated by the simultaneous participation of coordinated water molecules and malonate O atoms is interesting.…”

“…3), is achieved though the participation of three lattice water molecules [O11(H11A, H11B); O12(H12A, H12B); O13(H13A, H13B)] that act as stabilizing agents by saturating the uncoordinated malonate oxygen atoms through hydrogen bonding interactions (Table 3). It is to be noted that these lattice water molecules arrange in such a way that they produce water cluster mimics -actually, structures analogous to those of planar water tetramer [68], chair form water hexamer [69][70][71][72][73][74][75][76][77] and ring-shaped water octamer [78] are formed. In these cluster mimics, uncoordinated malonate O atoms of two symmetry related counterparts have replaced two water molecules in each of the above mentioned free water clusters motifs.…”

A hexagonal C3-symmetric (H2O)7 guest fits well into a C3-symmetric terbium complex cavity

“…2a), which is different from another hexagonal water cluster [13], in which the six water molecules trapped in the hexagonal cavity are rigidly coplanar and form a hexagon. Here, each water hexagon has C 3 -symmetry and six equivalent intracluster hydrogen bonds with the O5⋅⋅⋅O5 distance of 3.077 Å, comparatively longer than the corresponding values in ice I h (2.759 Å) [14] and another similar (H 2 O) 6 cluster (2.843 Å) [15]. However, they are shorter than those observed in the rigidly coplanar six-membered water ring (3.640 Å) [13].…”

“…2b) pattern similar to ice, I h . The difference of the water cluster with the literatures [14,15] is that there is half O6 water molecule in every (H 2 O) 6 cluster, because the occupancy ratio of O6 water molecule is 50%. The O6⋅⋅⋅O5 distances are 3.065 Å for hydrogen-bond 1, and 3.192 Å for hydrogen-bond 2 (Fig.…”

A Fully Integrated Nanotubular Yellow‐Green Phosphor from an Environmentally Friendly Eutectic Solvent

“…[9][10] While major attention has been focused on pore-size-related absorption properties, we have concurrently discovered extraordinary photoluminescence (PL) properties in openframework metal phosphates. [11][12][13][14][15][16] We discovered two metal phosphates, NTHU-4 [12] and NTHU-6, [13] which have novel nanoporous structures. These metal phosphates, unlike commercialized or developed color-conversion phosphors with emissions that originate from emitting activators doped into condensed host lattices, [17] contained no metal activators or any form of chromophores, but could emit intense yellow light under the excitation of near-ultraviolet (NUV) and blue light.…”