Solid‐State Coordination Chemistry: Hydrothermal Synthesis of Layered Vanadium Oxides with Interlayer Metal Coordination Complexes

Abstract

The oxides 1-4 are prepared in a single step I y the reaction of a precursor containing a transition or posl-transition element, the bidentate amine, and V,Oj in water at I70 C, and are isolated as highly crystalline, thin black plates. Since no external reducing agent is employed, the amine presumably serves i n this capacity. These materials, (L,M),. [VO,], where L = bidentate amine, M = Cu or Zn, 0.16<j,<0:33 and 2.335 ~12.83, share common structural features of vanadium oxide layers as well as a six-coordinate interlayer cation with four of the six coordination sites occupied by N atoms from two bidentate amine ligands and two sites from 0 atoms of the VO layel-. The layers are built up in all cases from VO, tetrahedra and or VO, square pyramids that are connected by edge-and corner-sharing inter- Hydrothermal Synthesis of Layered VanadiumLayered inorganic oxides constitute a diverse class of materials most of which share the common structural feature of a cationic guest that lies between the anionic oxide layers. The largest number of examples are known for materials composed largely of main group cations like clays, but solids with transition or post-transition elements like the layered double hydroxides"' and certain alkali metal titanatesc'' are known. Layered. and three-dimensional (3-D) oxides, containing both transition and main group metal cations, such as the Zr,I3], V,I4] and MoC5] phosphates and phosphonates, have also been studied. While many of these solids are noted for their unique characteristic of allowing a wide variety of organic or inorganic chemistries to be performed in the interlamellar region, the closed shell, diamagactions.The unprecedented structure of 1.18' consists of VO layers, which, when viewed parallel to [loo]. display a \cry pronounced sinusoidal ruffling with an amplitude of about 13 A and a period of about 15 8, (Fig. 1 left). These layers are composed solely of V 5 + 0 , tetrahedra each of which have a terminal vanadyl (V=O) group and share three corners with three neighboring VO, units (Fig. 1 right). Within each VO layer there are very large, roughly circular rings. which alternately lie in planes apnetic layers serve mainly as an inert nanoscale scaffolding. In contrast to these diamagnetic layers, several lamellar vanadium oxide solids have been prepared by high-temperature syntheses as well as the intercalation of alkali metal cations.'""' conductive organic and organic cations[6c1 between the layers of V20,. A one-diniensional ( 1 -D) metavanadate chain with coordinated Cu(NH,), groups has also been synthesized.

Hydrothermal Synthesis and Characterization of (H3N(CH2)4NH3)[V6O14]

“…2 A similar structure was already described in several layered vanadium oxides as the V 3 O 7 structure is one of the most prevalent of those found (6,(12)(13)(14). The square pyramids share edges to form zigzag chains, connected by corner-sharing tetrahedra (see Fig.…”

“…The (H 3 N(CH 2 ) 4 NH 3 )[V 6 O 14 ] compound reported in this paper exhibits the [V 3 O 7 ] structure already described in several layered vanadium oxide compounds (6,(12)(13)(14). Several parameters are important in the synthesis, the pH of the aqueous solution, the ratio of the reactants, the nature of the ions and the temperature.…”

Structural chemistry of vanadium oxides with open frameworks

“…(1) Zavalij et al (1997a); (2) Nazar et al (1996); (3) Zhang et al (1996b); (4) Zhang, DeBord et al (1996); (5) Chen et al (1999); (6) Zavalij et al (1999). example of single-chain structures with the VO 3 composition.…”

Hydrothermal Synthesis and Characterization of a Novel Sinusoidal Layer Structure Constructed From Polyoxometalates and Coordination Complex Fragments

“…In the layer, through the connection of each Ni(4) atom, the clusters are linked to one another along the a Ϫ b axis into a novel straight chain, as shown in Figure 2 (b), while through the connections alternatively at Ni(2) and Ni(3), each chain is connected with the adjacent ones along the a ϩ b axis, forming a novel sinusoidal layer. Figure 2c clearly shows that the layer displays a beautiful sinusoidal ruffling look, with an amplitude of about 20.8 Å , which is larger than those in [M(bpy) 2 ] 2 V 6 O 17 (M ϭ Zn, Ni, about 13 Å ) [19,20] and [Ni(Phen) 2 ] 2 V 4 O 11 (about 18.5 Å ), [21] whereas the period (about 25.9 Å ) is also far larger than those in [M(bpy) 2 ] 2 V 6 O 17 (M ϭ Zn, Ni, about 15 Å ) [19,20] and [Ni(Phen) 2 ] 2 V 4 O 11 (about 9.7 Å ). [21] These differences clearly originate from the fact that the layer of compound 1 is constructed from coordination complexes and bulky sphere-like [As 8 clusters linked into a two-dimensional sinusoidal layer structure.…”