Structural Systematics of 2/4-Nitrophenoxide Complexes of Closed-Shell Metal Ions. III 2/4-Nitrophenoxides of Univalent Heavy Metals

Abstract

Room-temperature single-crystal X-ray studies are recorded for 2- and 4-nitrophenoxide salts of silver(I) and thallium(I), M(2-np) and Tl(4-np) (anhydrous), and Ag(4-np).H₂O. Ag(2-np) is monoclinic, P2₁/c, a 9·012(4), b 5·743(5), c 12·594(5) Å, β 104·34(4)°, Z = 4; conventional R on |F| was 0·042 for N_o 1378 independent ‘observed’ (I > 3σ(I)) reflections. Tl(2-np) is monoclinic, C2/c, a 27·250(3), b 3·712(1), c 15·147(3) Å, β 114·41(1)°, Z = 8, R 0·025 for N_o 1346. Ag(4-np).H₂O is monoclinic, P2₁/a, a 5·613(6), b 13·191(7), c 9·844(5) Å, β 92·50(6)°, Z = 4, R 0 ·033 for N_o 622. Tl(4-np) is tetragonal, I 4₁/a, a 18·037(8), c 8·979(8) Å, Z = 16, R 0·043 for N_o 924. An acid salt of the latter, Tl(4-np).(4-npH)₃, triclinic, P^-1, a 11·861(8), b 11·45(1), c 11· 423(1) Å, α 114·00(6), β 109·78(5), γ 96·87(7)°, Z = 2, R 0·042 for N_o 3814, is isomorphous with its rubidium analogue. These comprise a novel array of structures: although the structures of the silver(I) complexes are two-dimensional sheets with familiar head-tail connecting ligands, a strong silver-aromatic carbon interaction is found in Ag(2-np) (Ag–C 2·496(5) Å). Tl(2-np) and Tl(4-np) both present unusual forms related to the stair-polymer and cubane adducts found in 1 : 1 coinage metal(I)/halide-unidentate nitrogen base adducts; Tl(2-np) is a double-stranded stair-polymer array, with the phenoxide oxygen atoms incorporated in the stair and the nitro oxygen atoms linking successive thallium atoms. The structure of Tl(4-np) is based on a tetranuclear cubane motif of ^-4 symmetry, [Tl(O-phenoxide)]₄, these being linked into a three-dimensional network by further Tl · · · O-nitro interactions from adjacent units. The structure of silver(I) picrate monohydrate, isomorphous with its sodium counterpart, is also recorded: monoclinic, C 2/m, a 12·818(7), b 20·208(8), c 3· 741(1) Å, β 88·25(3)°, Z = 4, R 0·047 for N_o 1042, void of any significant Ag · · · C contacts.