On THE CRYSTAL STRUCTURE AND SOME STRUCTUREDEPENDENT PROPERTIES OF LEAD(II) Β-Diketonates

Abstract

The structural chemistry of lead(ll) ß-diketonates is considered. A simple set of crystallographic and refinement data is presented for several lead(ll) complexes. Special attention is given to coordination modes of the ligand and specific intermolecular interaction. The influence of ligand and crystal structure on thermal properties and volatility of the complexes is specially discussed.

Synthesis, Structure, and Reactivity of Novel Intramolecularly Coordinated Organolead(II) Compounds

“…The Pb(1)−F(11) distance of 2.2762(7) Å is rather short compared with Pb−F in α‐PbF 2 [2.418(2), 2.439(8) Å]58 and β‐PbF 2 (2.573 Å) 59. Lead−fluorine distances of 3.04(6) and 3.30 Å have been reported for Pb(dhfa) 2 [Hdhfa = 1,5‐bis(undecafluorocyclohexyl)pentane‐2,4‐dione]60 and bis(2,2‐dimethyl‐6,6,7,7,8,8,8‐heptafluorooctane‐3,5‐dionato)lead,61 respectively. The lead atom exhibits a distorted octahedral configuration with four P=O oxygen atoms equatorial and F(4), F(11) in axial positions.…”

Lead(II): misleading or merely hermaphroditic?

“…The common observation that Pb(II) is found in a very asymmetric environment of a large number (often 10 or more) of possible donor atoms [7,8], however, has often meant that this problem has been by no means easily resolved. In a particular case [12], leadoxygen separations ranging from 2.38-3.07 Å, for example, have been considered, on the basis of bondvalence calculations, to be indicative of significant bonding interactions and there are numerous examples [5,[12][13][14][15][16][17][18] of 'long' Pb···X contacts that are nonetheless much shorter than the next most distant contacts and that have thus been taken as indicative of weak attractions. Uncertainty in the definition of the primary coordination sphere donor atoms in turn generates uncertainty in the identification of any coordination sphere 'hole' that might be taken to signify the presence of a stereochemically active lone pair [7,15].…”

Self‐Assembly of Coordination Polymers from Volatile PdII and PbII β‐Diketonate Derivatives through Metallophilic Interactions

“…The Pb(hfa) 2 molecules have a characteristic butterfly shape (pyramidal coordination). In the crystals, they are packed in the form of linear coordination polymers 3a. The structural units of [ trans ‐Pd(ki) 2 ]*[Pb(hfa) 2 ] ( 1 ) are neutral Pd(ki) 2 and Pb(hfa) 2 complexes incorporated into infinite chains as shown in Figures 1 and S1.1.…”

“…In contrast to the heterometallic compounds prepared from lead(II) β‐diketonates with copper(II),3 iron(II), and manganese(II)2j derivatives, in 1 we observed a significant change in the structure of the host molecules. Here, the Pb(hfa) 2 molecules lose their typical “butterfly” symmetry,3a and they become more flat and take the shape of a “bow tie”. In this heterometallic compound, each side of the distorted Pb(hfa) 2 molecule is attached to an almost unchanged molecule of trans ‐Pd(ki) 2 , which results in the characteristic zigzag coordination polymer (Figures 1 and S1.1) with alternating Pb–Pd–Pb segments in an ABACA manner with intermetallic distances of 3.65 Å (less than the sum of the van der Waals radii) 4i.…”

“…Preparation: The coordination polymers with the composition [ trans ‐Pd(ki) 2 ]*[Pb(hfa) 2 ] ( 1 ), [ cis ‐Pd(ki) 2 ]*[Pb(hfa) 2 ] ( 2 ), and [ trans ‐Pd(tmha) 2 ]*[Pb(hfa) 2 ] 2 ( 3 ) were obtained by simple cocrystallization of Pb(hfa) 2 ,3a Pd(ki) 2 ,3f and Pd(tmha) 2 3g. Equimolar amounts of the individual metal complexes were dissolved in chloroform/heptane (1:1, v/v).…”