Syntheses, characterizations and crystal structures of two lead(II) phosphonate-sulfonate hybrid materials

Hydrothermal reactions of lead(II) acetate with 5-sulfoisophthalic acid monosodium salt (NaH₂BTS) and N-(phosphonomethyl)-N-methylglycine, MeN(CH₂CO₂H)(CH₂PO₃H₂) (H₃L¹), or a new aminodiphosphonic acid, 3-Pyridyl-CH₂N(CH₂PO₃H₂)₂ (H₄L²), afforded two novel lead(II) phosphonate-sulfonate hybrids, namely, Pb₃[L¹][BTS][H₂O]·H₂O 1 and Pb₂[HL³][BTS]·H₂O 2 (H₂L³=3-Pyridyl-CH₂(Me)N(CH₂PO₃H₂)). H₂L³ was formed as a result of the decomposition of one phosphonate group in H₄L² during the reaction. Compound 1 crystallizes in the triclinic space group with a=9.9148(4) Å, b=10.4382(4) Å, c=10.6926(2) Å, α=96.495(2)°, β=110.599(2)°, γ=98.433(2)°, V=1008.31(6) Å³, and Z=2. The structure of compound 1 features a 3D network built from the interconnection of hexanuclear Pb₆(L¹)₂ units and 1D double chains of lead(II) carboxylate-sulfonate. Compound 2 crystallizes in the monoclinic space group P2₁/c with a=9.5403(7) Å, b=11.6170(8) Å, c=19.7351(15) Å, β=97.918(2)°, V=2166.4(3) Å³, and Z=4. Compound 2 has a 3D network structure built by the cross-linkage of 1D double chains of lead(II) phosphonates and 2D layers of lead(II) carboxylate-sulfonate.