10.1021/acs.inorgchem.6b01042.s001

Synthetic Tuning of Redox, Spectroscopic, and Photophysical Properties of {Mo<sub>6</sub>I<sub>8</sub>}<sup>4+</sup> Core Cluster Complexes by Terminal Carboxylate Ligands

Abstract

The reactions between the tetra-<i>n</i>-butylammonium salt of [{Mo<sub>6</sub>I<sub>8</sub>}­I<sub>6</sub>]<sup>2–</sup> and silver carboxylates RCOOAg (R = CH<sub>3</sub> (<b>1</b>), C­(CH<sub>3</sub>)<sub>3</sub> (<b>2</b>), α-C<sub>4</sub>H<sub>3</sub>O (<b>3</b>), C<sub>6</sub>H<sub>5</sub> (<b>4</b>), α-C<sub>10</sub>H<sub>7</sub> (<b>5</b>), or C<sub>2</sub>F<sub>5</sub> (<b>6</b>)) in CH<sub>2</sub>Cl<sub>2</sub> afforded new carboxylate complexes [{Mo<sub>6</sub>I<sub>8</sub>}­(RCOO)<sub>6</sub>]<sup>2–</sup>. The complexes were characterized by X-ray single-crystal diffraction and elemental analysis, cyclic/differential pulse voltammetry, and IR, NMR, and UV–visible spectroscopies. The emission properties of the complexes <b>1</b>–<b>6</b>, and those of the earlier reported complexes with R = CF<sub>3</sub> (<b>7</b>) and <i>n</i>-C<sub>3</sub>F<sub>7</sub> (<b>8</b>), were studied both in acetonitrile solution and in the solid state. In deaerated CH<sub>3</sub>CN at 298 K, all of the complexes <b>1</b>–<b>8</b> exhibit intense and long-lived emission with the quantum yield and lifetime being 0.48–0.73 and 283–359 μs, respectively. The oxidation (<i>E</i><sub>ox</sub>)/reduction (<i>E</i><sub>red</sub>) potentials of the complexes correlate linearly with the p<i>K</i><sub>a</sub> value of the terminal carboxylate ligands L = RCOO (p<i>K</i><sub>a</sub>(L)). Reflecting the p<i>K</i><sub>a</sub>(L) dependences of <i>E</i><sub>ox</sub>/<i>E</i><sub>red</sub>, the emission energy (ν<sub>em</sub>) of the complexes was also shown to correlate with p<i>K</i><sub>a</sub>(L). The present study successfully demonstrates synthetic tuning of the redox, spectroscopic, and photophysical characteristics of a {Mo<sub>6</sub>I<sub>8</sub>}<sup>4+</sup>-based cluster complex with p<i>K</i><sub>a</sub>(L)

Similar works

Full text

thumbnail-image
oai:figshare.com:article/3551895Last time updated on 2/12/2018

This paper was published in FigShare.

Having an issue?

Is data on this page outdated, violates copyrights or anything else? Report the problem now and we will take corresponding actions after reviewing your request.