Untitled

Abstract

The reaction of the organolithium derivative {2,6- (5) which was characterized by 1 H, 13 C and 31 P NMR spectroscopy and single crystal X-ray analysis. Ab initio MO-calculations reveal the intramolecular O···C distances in 5 of 2.952(4) and 2.988(5) Å being shorter than the sum of the van der Waals radii of oxygen and carbon to be the result

The First O,C,S-Coordinating Pincer-Type Ligand and Its Application to the Synthesis of a Triorganotin Cation Stabilized by Two Different Donor Atoms

“…As in compound 1 , the sulfur atom S(1) points to H(1) with a distance of 2.75(2) Å, whereas the O(3) oxygen atom points away, with the consequence of the isopropoxy oxygen atom O(2‘ ‘) approaching H(1) at a distance of 2.77(2) Å. A similar situation was observed for the phosphoryl groups in the related compounds 1,3-[P(O)(OR) 2 ] 2 -5- t -Bu-C 6 H 3 (R = Et, i -Pr). , …”

Heteroleptic Organostannylenes and an Organoplumbylene Bearing Phosphorus‐Containing Pincer‐Type Ligands – Structural Variations and Insights into the Configurational Stability

“…The two phosphorus atoms in 3 – 5 and 6 are crystallographically nonequivalent and, exemplarily, for compound 3 this is nicely reflected by a 31 P{ 1 H}MAS NMR (161.98 MHz) spectrum showing two equally intense resonances at δ = 33.2 and 34.4. The C(1)–C(2)–P(1)/C(1)–C(6)–P(2) angles (α/α′ angles)11h between 114.9(2) ( 6 ) and 117.3(2)° ( 4 ) support the idea that the Sn–O interactions are attractive. Similar angles (114.9(5)/114.5(3)°) were observed for the diorganotin dichloride [4‐ t Bu‐2,6‐{P(O)(OEt) 2 } 2 C 6 H 2 ]SnPhCl 2 11o.…”

“…Like in its ethoxy‐substituted analogue 5‐ t Bu‐1,3‐{P(O)(OEt) 2 } 2 C 6 H 3 ,11h both P=O oxygen atoms O(1) and O(2) point away from the hydrogen atom H(1), but in contrast to the latter they are only slightly displaced from the aromatic plane. There are intramolecular O(1)···H(3) and O(2)···H(5) distances of 2.65(4) and 2.68(4) Å, respectively, that are shorter than the van der Waals distances12 of oxygen (1.50 Å) and hydrogen (1.20–1.45 Å).…”

The First [4+2]-Coordinated Tetraorganolead Compound: Synthesis, Structure and Conversion into a Triorganolead Cation, a Benzoxaphosphaplumbole, and Diorganolead Dihalides

“…Slightly shorter intramolecular O···Pb distances of 2.915 (8) [37], 1246 cm Ϫ1 (2, M ϭ Pb), and 1233 cm Ϫ1 (M ϭ Sn) [35] and suggest the strength of the intramolecular O···M coordination to increase in the sequence M ϭ Si < M ϭ Pb < M ϭ Sn. Usually such comparisons are made on the basis of Pauling-type bond orders [66][67][68] but in the actual case this is not possible because a reliable covalent (2)ϪP(1) and C(1)-C(6)-P(2) angles (α, αЈ angles [70]) of 122.3(2) and 122.3(2)°, respectively, are rather similar to the corresponding angles in the related organosilicon [37] and organotin compounds [35].…”

“…ECE-coordinating pincer-type ligands of the general type [2,6-(ECH 2 ) 2 C 6 H 3 ] Ϫ containing mainly E ϭ nitrogen [1Ϫ20], phosphorus [1, 20Ϫ31], and sulfur [1, 32Ϫ34] donors have received great interest as result of their potential (i) to stabilize organometallic compounds of both main group and transition metals with the metal atoms having unusual coordination numbers and (ii) to tune the reactiv- [37,42] and tetraorganotin [35] compounds, of triorganosilicon [43] and triorganotin [38,41,44] cations, of benzoxasilaphospholes [43] and benzoxaphosphastannoles [38,41], and of heteroleptic tin(II) compounds [40].…”