Synthesis and structural characterization of (C14H16N2)3(C14H17N2)2[β-Mo8O26]

Abstract

A novel polyoxomolybdate (C 14 H 16 N 2) 3 (C 14 H 17 N 2) 2 [β-Mo 8 O 26 ](1) has been synthesized from hydrothermal reaction of tolidine and molybdenum trioxide in water and characterized by its IR and UV spectra, 1 H NMR, cyclic voltammetry and single crystal X-ray diffraction. Compound 1 crystallizes in the triclinic crystal system, space group Pī, with the crystal cell parameters of a=11.5360 Å, b=11.6080 Å, c=15.2520 Å, α=72.50 • , β=79.46 • , γ =86.91 • , V =1915.00 Å 3 and Z=1. The asymmetric unit of the crystal structure of (C 14 H 16 N 2) 3 (C 14 H 17 N 2) 2 [β-Mo 8 O 26 ] contains β-octamolybdate [β-Mo 8 O 26 ] 4− anions, two tolidine molecules and shows the presence of monoprotonated tolidine cations. One tolidine molecule and a β-Mo 8 O 26 polyanions species lie across crystallographic inversion centres while the two tolidine molecules occupy general sites.

Non-hydrothermal synthesis and structure determination of two new β-octamolybdate (VI) stabilized with dialkylammonium counterions

“…In addition, for both compounds (1) and 2 . This was also reported in the literature for similar compounds but was not yet interpreted [33,34]. We suggest here that some variations in the MoeO bond lengths in the b-[Mo 8 O 26 ] 4cluster can be explained at least partially by the fact that the junction of two MoO 6 octahedra by edge sharing brings the two positive (Mo VIþ ) ions closer, which enhances their mutual repulsive interaction (Coulomb interaction).…”

Assembly of organic moiety with metal-oxide cluster to generate a new three dimensional supramolecular/hydrogen bonded network based on isopolymolybdate

“…The organic groups and water molecules reside between chains formed by inorganic octa-molybdate clusters as shown in figure 3. The [Mo 8 O 26 ] 4− anion is a typical β-structure octa-molybdate, 25 BVS calculations, 26 revealed that all the molybdenum atoms have valence sums ranging from 5.909 to 5.976, with an average value of 5.946, close to the ideal value of 6 for Mo VI (table 3). The result is consistent with the formula of compound 1 given by X-ray structure determination.…”

“…The thermal gravimetric curve of (C 2 H 6 N 4 ) 2 [β-Mo 8 O 26 ].4H 2 O (1) ( figure S2 in Supplementary Information) exhibits one weight loss step in the temperature range 55-154 • C corresponding to two endothermic peaks at 111 and 140 • C are due to the dehydration of 4 water molecules. The observed weight loss (4.75%) is in agreement with the calculated value (5.04%).…”

“…[2][3][4][5][6][7] Furthermore, it is noteworthy that an important field in the polyoxomolybdates is the structural chemistry of the well-known polyoxomolybdate anion, [Mo 8 O 26 ] 4− , 8 it was first described in organic-inorganic hybrid materials by Hagrman et al 9 Up to now, eight isomeric forms, the α-, β-, γ -, δ-, ε-, ζ -, η-, and θ-isomer, were prepared in discrete presentations. [10][11][12] This current description of the octa-molybdate structure, however, will focus on the two most prominent isomeric forms, [α-Mo 8 Recently, the interest is extended to the modification of POM structure by introduction of organic derivatives. 14 As the POM anions contain many oxygen atoms which act as good hydrogen bond acceptors, bonding these POMs with organic molecules having many hydrogen atoms give rise to interesting supramolecular chemistry.…”

A Rearrangement Reaction to Yield a NH4+ Ion Driven by Polyoxometalate Formation

“…All these values almost match the vibrational features reported for the β-isomer of the octamolybdate in the literature. 51,52 The strong peak at 1214 cm −1 can be attributed to the C−N stretch. The peaks at 1380 and 1470 cm −1 can be attributed to CH 2 and CH 3 bending of the ethyl groups, and the peaks at 2872 and 2968 cm −1 can be attributed to the C−H stretch.…”