Structural and Solid-State 31P N.M.R. Studies of Tetrameric 1:1 Butyldiphenylphosphine Complexes of Silver(I) Halides

Abstract

Tetrameric 1:1 complexes of butyldiphenylphosphine (PPh2Bu) with silver halides AgX (X = Cl , Br and I) have been synthesized, and characterized in the solid state by single-crystal X-ray diffraction studies and solid-state 31P n.m.r. Crystals of [(PPh2Bu) AgCl ]4 and [(PPh2Bu) AgBr ]4 are isostructural, crystallizing in the tetragonal space group 14 with a 16.853(4), c 11.697(4) Ǻ and R 0.060 for 999 'observed' reflections for X = Cl, and a 16.944(4), c 11.893(9) Ǻ and R 0.044 for 835 'observed' reflections for X = Br. The structures consist of 'cubane' units with core distances of Ag-P 2.365(8), Ag- Cl 2.712(7), 2.682(6) and 2.569(6) Ǻ for the chloride, and Ag-P 2.408(6), Ag-Br 2.819(3), 2.806(3) and 2.670(3) Ǻ for the bromide. Crystals of [(PPh2Bu) AgI ]4 crystallize in the same space group with similar cell dimensions, a 16.559(4) and c 12.819(3) Ǻ, and R 0.053 for 638 'observed' reflections. However, the tetramers in this complex are rotated by 45° around the c axis with apparent relaxation of strain at the Ag-P bond. The ligand conformation is such that the butyl groups are oriented along the c axis rather than lying in the ab plane as found for the chloride and bromide structures. The bond distances for the I3AgP core are Ag-P 2.43(1), Ag-I 2.928(4), 2.882(4) and 2.885(4) Ǻ. The ligand substituents in this complex exhibit very high thermal motion although no disorder is resolved. Solid-state CPMAS 31P n.m.r. spectra of the chloride and bromide complexes each show a simple doublet with line spacing of 640 and 595 Hz respectively assignable to 1J(107,109Ag,31P) scalar coupling. The spectrum of the iodide complex, however, consists of a broad single peak suggestive of a high degree of disorder in the crystal lattice, consistent with the structural results.

Egg‐ or cell culture‐derived hemagglutinin mutations impair virus stability and antigen content of inactivated influenza vaccines

“…Complex 2 is comprised of a central Ag I atom bonded to an iodide ion and coordinated to the tellurium atoms of three neutral ligands B by terminal P=Te bonds. Although phosphane complexes of AgI are known,9 the preferential coordination of Ag I to the soft tellurium atom rather than the P III donor site in B is expected. The arrangement of 2 can best be described as a distorted tetrahedron with bond angles around the central Ag atom ranging from 102.92(2)° to 114.51(5)°.…”

Coordination complexes of silver(I) with tertiary phosphine and related ligands

“…More sterically demanding species tend to relieve strain by forming the step structure 2 rather than the cubane structure 1, since the three-coordinate metal sites and dibridging halides in the step structure 2 are less crowded. Thus, the trialkylphosphine PEt 3 yields tetrameric cubane clusters [AgX(PEt 3 )] 4 (X = Cl − , Br − [13] and I − [14]) and the reaction of equimolar ratios of PPh 2 Bu with silver(I) halides yields tetrameric cubane structures of type [AgX(PPh 2 Bu)] 4 (X = Cl − , Br − and I − ) [15]. However, the isolation and characterisation of cubane -[AgI(PPh 3 )] 4 [12,16] from CHCl 3 /Et 2 O and the step analogue from CH 2 Cl 2 /Et 2 O [11,17], as well as the isolation of the sterically unfavoured cubane complexes [AgI(PCy 3 )] 4 (Cy = cyclohexyl) [18], [CuI(PPh 3 )] 4 [19] and [CuBr(P t Bu 3 )] 4 [20], shows that the nature of the determining factors are not clearly understood.…”

catena-Poly[silver(I)-μ2-4,4′-bipyridine-κ2N:N′-μ3-chlorido]: self-assembly of a two-dimensional bilayer silver(I) coordination polymer from AgCl and a bipodal spacer

“…to the Ag centers (Bowen et al, 1994;Zartilas et al, 2009). The three 3 -Cl atoms and one Ag atom of (I) are coplanar, with maximum and minimum Cl-Ag-Cl angles of 160.94 (5) and 99.53 (3) , respectively.…”