Substitution of the laser borane anti-B18H22 with pyridine: a structural and photophysical study of some unusually structured acropolyhedral boron hydrides

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388980%3A_____%2F18%3A00486863" target="_blank" >RIV/61388980:_____/18:00486863 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1039/c7dt03823b" target="_blank" >http://dx.doi.org/10.1039/c7dt03823b</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c7dt03823b" target="_blank" >10.1039/c7dt03823b</a>

Result language

angličtina

Original language name

Substitution of the laser borane anti-B18H22 with pyridine: a structural and photophysical study of some unusually structured acropolyhedral boron hydrides

Original language description

Reaction of anti-B18H22 1 with pyridine in neutral solvents gives sparingly soluble B16H18-3', 8'-Py-2 3a as the major product (ca. 53%) and B18H20-6', 9'-Py-2 2 (ca. 15%) as the minor product, with small quantities of B18H20-8'-Py 4 (ca. 1%) also being formed. The three new compounds 2, 3a and 4 are characterized by single-crystal X-ray diffraction analyses and by multinuclear multiple-resonance NMR spectroscopy. Compound 2 is of ten-vertex nido: ten-vertex arachno two-atoms-in-common architecture, long postulated for a species with borons-only cluster constitution, but previously elusive. Compound 3a is of unprecedented ten-vertex nido: eight-vertex arachno two-atoms-in-common architecture. The singlecrystal X-ray diffraction analysis for the picoline derivative B16H18(NC5H4Me)(2) 3b, similarly obtained, is also presented. B18H20Py 4 is also previously unreported but is of known ten-vertex nido: ten-vertex nido twoatoms- in-common architecture of anti configuration, but now with the pyridine ligand positioned differently to other reported examples of B18H20L compounds. Factors behind the remarkably low solubility of 3a and 3b are elucidated in terms of electrostatic potential (ESP) calculations, polarity, and van der Waals complementarities. In view of contemporary developing high interest in the fluorescent properties of macropolyhedral boron-containing species, a detailed assessment of the photophysical characteristics of 3a and 4 is also presented. In contrast to the thermochromic fluorescence of 2 (from 620 nm brick-red at room temperature to 585 nm yellow at 8 K, quantum yield 0.15), compound 3a is only weakly phosphorescent in the yellow region (590 nm, quantum yield 0.01), whereas compound 4 exhibits no luminescence. The far more photoactive nature of compound 2 is associated with S-1 excited-state minima structures that differ from each other only by the relative rotational positions of the pyridine substituents on its disubstituted ten-vertex {arachno-B10Py2}-subcluster. The wavelength and relative intensity of fluorescence from these structures depends on the rotational positions of the pyridine ligands, which in turn are influenced by temperature and/or rotational inhibition in the solid-state.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10402 - Inorganic and nuclear chemistry

Project

<a href="/en/project/GA18-20286S" target="_blank" >GA18-20286S: Boron Hydride Cluster Lasers: Understanding the Chemical and Structural Factors that Determine the Photophysics of anti-B18H22 and its Derivatives</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Dalton Transactions

ISSN

1477-9226

e-ISSN

—

Volume of the periodical

47

Issue of the periodical within the volume

5

Country of publishing house

GB - UNITED KINGDOM

Number of pages

17

Pages from-to

1709-1725

UT code for WoS article

000423760500040

EID of the result in the Scopus database

2-s2.0-85041317988