Stepwise isolation of low-valent, low-coordinate Sn and Pb mono- and dications in the coordination sphere of platinum

• Published in: Chemical science (Cambridge) Vol. 6; no. 1; pp. 425 - 435
• Main Authors: Braunschweig, Holger, Celik, Mehmet Ali, Dewhurst, Rian D, Heid, Magdalena, Hupp, Florian, Sen, Sakya S
• Format: Journal Article
• Language: English
• Published: England 01-01-2015
• Subjects: Covalence; Dispersions; Ionic interactions; Lead (metal); Mathematical analysis; Platinum; Tin; Transition metals
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/c4sc02948h

Synthetic access to low-coordinate Pb mono- and dications is in general impeded due to their poor solubility and highly electrophilic nature. However, the electrophilicity of these cations can be tamed by attaching them to electron-rich transition metals. Following this principle we have isolated low-valent Pb mono- ([(Cy
P)
Pt-PbCl]
[AlCl
]
,
) and dications ([(Cy
P)
Pt(Pb)][AlCl
]
,
) in the coordination sphere of platinum. The same approach then has been implemented for the isolation of analogous low-valent Sn mono- (
) and dications (
). An energy decomposition analysis (EDA-NOCV) was performed to investigate the nature of Pt-Pb and Pb-Cl bonding in [(Cy
P)
Pt(PbCl
)] (
),
and
. The results show that the Pt-Pb bonds in
and
are electron-sharing in nature, whereas that of the precursor
is a dative bond. The breakdown of attractive interactions in
,
and
reveals that the ionic interactions in the analyzed Pt-Pb and Pb-Cl bonds are always stronger than the covalent interactions, except for the Pb-Cl bond in
. The calculated D3 dispersion energies show that dispersion interactions play a key role in the thermodynamic stability of
,
and
.