Isolation of Elusive HAsAsH in a Crystalline Diuranium(IV) Complex.
The HAsAsH molecule has hitherto only been proposed tentatively as a short-lived species generated in electrochemical or microwave-plasma experiments. After two centuries of inconclusive or disproven claims of HAsAsH formation in the condensed phase, we report the isolation and structural authentication of HAsAsH in the diuranium(IV) complex [{U(Tren(TIPS) )}2 (μ-η(2) :η(2) -As2 H2 )] (3, Tren(TIPS) =N(CH2 CH2 NSiPr(i) 3 )3 ; Pr(i) =CH(CH3 )2 ). Complex 3 was prepared by deprotonation and oxidative homocoupling of an arsenide precursor. Characterization and computational data are consistent with back-bonding-type interactions from uranium to the HAsAsH π*-orbital. This experimentally confirms the theoretically predicted excellent π-acceptor character of HAsAsH, and is tantamount to full reduction to the diarsane-1,2-diide form.
School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL (UK).
Benedict M
BM
Gardner
Institut of Inorganic Chemistry, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg (Germany).
Gábor
G
Balázs
Institut of Inorganic Chemistry, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg (Germany). manfred.scheer@ur.de.
Manfred
M
Scheer
School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL (UK).
Ashley J
AJ
Wooles
School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL (UK).
Floriana
F
Tuna
School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL (UK).
Eric J L
EJ
McInnes
School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD (UK).
Jonathan
J
McMaster
School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD (UK).
William
W
Lewis
School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD (UK).
Alexander J
AJ
Blake
School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL (UK). steve.liddle@manchester.ac.uk.
Stephen T
ST
Liddle
arsenic; back-bonding; density functional theory; diarsene; uranium