Metal Complexes of Bredt Olefins: Synthesis and Structure of Bicyclo[4.2.1]non‐1(8)‐enebis(triphenylphosphane)platinum(0)

Abstract

Reversible stabilization of a Bredt olefin has been accomplished for the first time with a platinum(0) compound. In complex (3) (X‐ray structure analysis) the olefin has the same conformation as free (2) (force field calculations). Treatment of the complex with CS2 regenerates isomer‐free (2).

Stereochemistry of Platinum Organometallics

“…One derivative contains three such molecules [72] and another one derivatives has four such molecules [73]. In these derivatives the platinum atoms are found in the oxidation states of zero (x5) [38][39][40][41][42], +2 (x 27) [12, 37, 43-65, 72, 73] and +4 (x 6) [66][67][68][69][70][71]. The derivatives belong to the triclinic (x 17), monoclinic (x 16) and orthorhombic (x 5) classes.…”

“…In another three Pt(0) derivatives Pt( 2 -CL)(PPh 3 ) 2 (CL is HC=C 6 H 10 OH [39], had [40] and bcn [41] a homobidentate (C, C´-donors ) ligand and two PPh 3 ligands create a tetrahedral arrangement about each Pt(0) atom (PtC 2 P 2 ), with differing degrees of distortion. In Pt 0 ( 2 -sti)( 2 -chirophos) [42] a homobidentate sti (C, C´-donors and chirophos (P,P´-donors) ligands form two metallocycles, three -and fivemembered, with the mean C -Pt -C and P -Pt -P bite angles of 39.3(2)°, and 87.13( 6)° (molecule 1), and 39.9(3)° and 86.55(6)° (molecule 2).…”

“…There are thirty six examples (Pt(0) [38][39][40][41][42], Pt(II) [12,37,, Pt(IV) [66][67][68][69][70][71]) which contains two crystallographicaly independent molecules. One example, [Pt(II)( 4 -bdpb)Cl]Cl [72] contains three such molecules and another one [Pt(II)( 2 -dmaen)( 2 -msedpa)].ClO 4 [73] contains even four such molecules.…”

“…In this series of distortion isomers the Pt(0) atoms are tetrahedrally coordinated (PtP 3 C [7,8], PtC 4 [38], PtC 2 P 2 [39][40][41][42], PtC 2 PPt´ [84,87]). The mean Pt(0) -L bond distances elongated in the order: 1.86 Å (CO) < 2.055 Å ( -CO) The Pt(I) is tetrahedrally coordinated (PtCSPPt´) [74] with the mean Pt(1) -L bond distances elongated in the order: 1.845 Å (CO) < 2.263 Å ( -S) < 2.267 Å ( -PL) < (3) 11.991 (4) 22.602 (4) 90.50 (1) PtC2P2 C P 2.05 (2) 1.97 (2) 2.340 (4) 2.286 (4) C,C P,P C,P 84.3 (7) 100.3 (1) 87.7 (5,4.6) 171.9(4,4.7)…”