Iridium(III) Amine Complexes as High-Stability Structure-Directing Agents for the Synthesis of Metal Phosphates

The metal complexes Ir(en) 3 3+ and M((±)chxn) 3 3+ (en = 1,2-diaminoethane, chxn = trans -1,2-diaminocyclohexane, M = Ir or Co) have been used to synthesize the layered compound Δ,Λ-Ir(en) 3 [Al 3 P 4 O 16 ]· x H 2 O ( x ≈ 3.45) and the chain compounds M(chxn) 3 [Al 2 P 3 O 12 ]· x H 2 O ( x ≈ 4). The chain compounds contain two of the eight possible isomeric forms of the cation, Λ(lel 2 ob)-[M( S, S -chxn) 2 ( R, R -chxn)] 3+ and its mirror image Δ(lel 2 ob)-[M( R, R -chxn) 2 ( S, S -chxn)] 3+ . Microcrystals of the Ir(en) 3 3+ and Ir(chxn) 3 3+ containing AlPOs were structurally characterized using synchrotron radiation. Δ,Λ-Ir(en) 3 [Al 3 P 4 O 16 ]· x H 2 O is isomorphous with the previously reported material Δ,Λ-Co(en) 3 [Al 3 P 4 O 16 ]· x H 2 O. The materials prepared using Co((±)chxn) 3 3+ and Ir((±)chxn) 3 3+ are also isostructural with one another and contain a new type of aluminophosphate chain. The use of Ir(III) in the structure-directing metal complex enabled the use of much harsher hydrothermal conditions for the metal phosphate synthesis than could be employed with the corresponding Co(III) complexes. Ir(C 2 N 2 H 8 ) 3 [Al 3 P 4 O 16 ]·3.45H 2 O: M r = 895.5, orthorhombic, Pnna, a = 8.548(5), b = 21.983(14), c = 13.970(9) Å, V = 2625(3) Å 3, Z = 4, ρ calc = 2.266 g cm - 3, λ = 1.1167 Å, μ = 14.03 mm - 1, F (000) = 1762, T = 293 K, R F = 0.128 for 954 reflections I >2σ( I ). Ir(C 6 N 2 H 14 ) 3 Al 2 P 3 O 12 ·4H 2 O: M r = 945.7, triclinic, P 1̄, a = 9.649(5), b = 12.365(9), c = 16.083(8) Å, α =100.02(6), β = 101.64(5), γ = 104.75(6)°, V = 1765(2) Å 3, Z = 2, ρ calc = 1.779 g cm - 3, λ = 1.1167 Å, μ = 9.747 mm - 1, F (000) = 952, T = 293 K, R F = 0.128 for 966 reflections I > 2σ( I ).