Synthesis and structure of [Pb(μ-P-t-Bu2)P-t-Bu2]2. A perphosphido lead(II) dimer

A Stabilized Bisphosphanylsilylene and Its Heavier Congeners

“…Dimeric plumbylene 4 is isostructural with trans ‐ 2 showing a planar four membered ring and a staggered conformation of the ferrocene backbone. The P endo –Pb contacts (2.743(4) and 2.752(4) Å) are slightly longer than the P exo −Pb bonds (2.706(4) Å) and fit in between the reported values of cis (P exo −Pb: 2.696(7) Å, P endo −Pb: 2.747–2.796 Å) and trans (P exo −Pb: 2.781(4), P endo −Pb 2.812(3) Å) oriented P 2 Pb 2 compounds formally derived from acyclic plumbylenes. Compared to the latter compounds the sum of angles around Pb is with 274.43° about 10 % less in 4 indicating a more pyramidal coordination environment around this atom for the latter.…”

“…Reaction of lithium phosphanide 1 with tetrel dihalides of tin through lead, gave very diverse results. Reaction of SnCl 2 or SnBr 2 with 1 resulted in formation of the dimeric stannylene 2 (Scheme ) which showed characteristic NMR parameters and coupling patterns ( δ ( 119 Sn)=+419 ppm (td, 1 J SnP =1204 Hz, 1 J SnP =735 Hz), ( δ ( 31 P)=−31.4 ppm (P exo ) and −92.6 ppm (P endo )) in agreement with other dimeric phosphanylstannylenes featuring a mutual donor–acceptor motif based on NMR spectroscopy . X‐ray diffraction on several single crystals confirmed the structural motif and revealed the presence of cis and trans isomers (Figure ) which are difficult to distinguish based on heteronuclear NMR in solution, owing to two overlapping sets of signals for both isomers.…”

“…The trans isomer of 2 features a centrosymmetric dimeric Fe(C 5 H 4 P t Bu) 2 Sn unit, whereas its cis counterpart exhibits a puckered four membered ring. These central structural geometries are consistent with related compounds containing P 2 E 2 units (E=Pb, Ge) formally derived from acyclic phosphanyl tetrylenes . In trans ‐ 2 ( 2 a ) the center of inversion is located in the middle of the planar four membered ring with μ bridging phosphorus atoms having Sn−P bond lengths of 2.623(2) and 2.657(2) Å.…”

Dimere Dialkylphosphanylgermylene: Ylidische Diphosphadigermetane

“…Im (cis-)dimeren Di[bis(trimethylsilyl)phosphanyl]plumbylen betra È gt der Unterschied der terminalen und verbru È ckenden Pb±P Absta È nde etwa 7 pm [12], in Bis(di-t-butylphosphanyl)plumbylen ist die Differenz hingegen nur 3 pm [24]. Øhnlich gering ist der Unterschied der Ge±P Absta È nde in 5 b (verbru È ckend: 242, terminal 239 pm).…”

Lead Coordination and Organometallic Compounds: Classification and Analysis of Crystallographic and Structural Data

“…There are two derivatives of the general formula [Pb 2 M 3 ]' 2 , where Μ is a chalcogen, Se [160] orTe [161], and these are isostructural ( [82,85,102,[162][163][164][165][166], or two N-donor ligands [167], two S-donor ligands [168][169][170][171], two P-donor ligands [172,173] or two Se-donor ligands [174], Distorted edge-shared trigonal [167][168][169][172][173][174], tetrahedra [102,162,163,166], trigonal bipyramidal [85]. pseudo-octahedral [164,165] and heptahedral [82,170,171] are observed.…”