Lewis-base adducts of group 1B metal(I) compounds. Part 13. Crystal structure determinations of tetrakis(triphenylphosphine)-copper(I) and -silver(I) perchlorates, bis(pyridine)bis(triphenyl-phosphine)copper(I) perchlorate, (2,2′-bipyridyl)bis(triphenyl-phosphine)copper(I) perchlorate, and tetrahydroboratobis-(triphenylphosphine)copper(I)–pyridine (1/0.5)

Abstract

The crystal structures of [Cu(PPh₃)₄]ClO₄(1) and [Ag(PPh₃)₄]ClO₄(2) have been determined by single-crystal X-ray diffraction methods at 295 K, being refined by least-squares methods to residuals of 0.10 and 0.08 for 591 and 1 294 independent ‘observed’ reflections respectively. The two compounds are isomorphous (rhombohedral, space group R, and Z= 2) with a= 19.02(2)Å, α= 44.06(6)° and a= 19.085(5)Å, α= 43.90(1)° respectively; the cation lies on a site of 3 symmetry, while the anion is disordered about a site of symmetry. The metal-atom geometry is pseudo-tetrahedrai [Cu–P = 2.60(1), 2.52(1)Å; Ag–P = 2.650(2)Å, with all P–M–P angles lying between 109.3 and 109.7 °]. For the structure determination of [Cu(PPh₃)₂(py)₂]ClO₄(3) obtained by the recrystallization of [Cu(PPh₃)₄]ClO₄ from pyridine (py), 2 843 ‘observed’ reflections were refined to a residual of 0.052. Crystals are triclinic, space group P, with a= 15.599(4), b= 13.413(4), c= 10.982(4)Å, α= 79.51(3), β= 70.47(3), γ= 860.3(3)°, and Z= 2. Cu–P = 2.271(4), 2.295(3)Å and Cu–N = 2.102(7), 2.115(8)Å in a pseudo-tetrahedral copper(I) environment, with P–Cu–P = 115.85(9)° and N–Cu–N = 101.5(2)°. The 2,2′-bipyridyl (bipy) analogue [Cu(PPh₃)₂(bipy)]ClO₄(4) is monoclinic, space group P2₁/c, with a= 10.210(3), b= 15.085(4), c= 28.455(9)Å, β= 109.13(2)°, and Z= 4. Cu–P = 2.246(3), 2.256(3)Å and Cu–N = 2.056(8), 2.113(9)Å, with P–Cu–P = 125.4(1) and N–Cu–N = 79.6(4)°. R was 0.081 for 2 605 reflections. [Cu(BH₄)(PPh₃)₂], by contrast, yields a hemipyridine solvate, (5), on recrystallization from pyridine; crystals are triclinic, space group P, with a= 12.849(6), b= 10.319(5), c= 13.618(6)Å, α= 102.91(4), β= 101.91(4)γ= 73.42(4)°, and Z= 2. The structure was refined to a residual of 0.051 for 3 633 independent ‘observed’ reflections, and is isomorphous with the hemibenzene solvates of [CuX(PPh₃)₂](X = Cl or Br) and [AuCl(PPh₃)₂].