Distortion Coordinate for Five-Coordinated Tin. A Model for Nucleophilic Substitution. Synthesis and Structure of Hypervalent Anionic (Cyanoethylenedithiolato)stannates

Article abstract of DOI:10.1021/ja00224a024

Reaction of Ph3SnCl and RSnCl3 (R = Me, n-Bu) with R4N⁺Cl^- and disodium maleonitriledithiolate, Na2(mnt), yield the monostannole <((CN)2C2S2)SnPh3> (1) and the new distannoles <((CN)2C2S2)2SnR> .X-ray analysis reveals the geometries of 1 as trigonal bipyramidal and 2 and 3 as square pyramidal.The tristannole <((CN)2C2S2)3Sn> (4) results from Sn-C bond cleavage of PhSnCl3 in a hydrolysis reaction with Na2(mnt) and Et4N⁺Cl^-.The geometrical data on organotin complexes containing ring unsaturation, 1-3, and related anionic five-coordinated tin compounds show that the distortion coordinate expressing solid-state nonrigidity is the Berry pseudorotational coordinate.As a result of this work, one is able for the first time to compare structural principles for five-coordinated compounds established for other main-group 14 and 15 elements.Their significance in reaction mechanisms is discussed.Stannole 1 crystallizes in the monoclinic space group Cc with a = 16.780 (3) Angstroem, b = 9.433 (2) Angstroem, c = 16.858 (3) Angstroem, β = 96.85 (1)deg, Z = 4.Distannole 2 crystallizes in the monoclinic space group P2₁/c with a = 14.997 (3) Angstroem, b = 11.730 (3) Angstroem, c = 14.167 (3) Angstroem, β = 107.6 (2)deg, and Z = 4.Distannole 3 crystallyzes in the monoclinic space group P2₁/m with a = 9.016 (2) Angstroem, b = 10.906 (3) Angstroem, c = 14.310 (2) Angstroem, β = 98.35 (1)deg, and Z = 2.Tristannole 4 crystallizes in the monoclinic space group C2/2 with a = 9.434 (2) Angstroem, b = 25.123 (6) Angstroem, c = 12.773 (1) Angstroem, β = 101.76 (1)deg, and Z = 4.The final conventional unweighted agreement factors were 0.024 (1), 0.041 (2), 0.038 (3), and 0.035 (4).