Structural Systematics of 2/4-Nitrophenoxide Complexes of Closed-Shell Metal Ions. I 2-Nitrophenoxides of Group 1

Abstract

Room-temperature, single-crystal X-ray studies are recorded for the variously hydrated Group 1 metal derivatives of 2-nitrophenol (2-npH = C₆H₅NO₃). A provisional determination is reported for Li(2-np).½H₂O, set as monoclinic, P21/c, a 3·535(3), b 15·06(1), c 24·42(2) Å, β 91·7(1)°, Z = 8, conventional R on F currently 0·18 for N_o 875 ‘observed’ (I > 3σ(I)) reflections. Na(2-np).H₂O is monoclinic, C2/c, a 34 ·23(2), b 3·624(4), c 35·48(2) Å, β 91·24(4)°, Z = 24, R 0·060 for N_o 1371. Rb(2-np).½ H₂O is monoclinic, C2/c (isomorphous with the previously determined potassium analogue), a 25·269(9), b 5·381(5), c 12·010(3) Å, β 105·35(3)°, Z = 8, R 0·046 for N_o 1380. Cs(2-np).½H₂O is monoclinic, P2₁/n, a 7·648(3), b 26·19(1), c 8·713(6) Å, β 111·75(2)°, Z = 8, R 0·061 for N_o 2347. All compounds except the lithium derivative are two-dimensional polymeric sheets in which the aromatic rings project to either side of a core of metal atoms coordinated by a web of 2-nitrophenoxide oxygen atoms in various bridging functionalities. The lithium compound is a novel ‘stair’ polymer with two crystallographically independent lithium atoms at successive independent Li–O crossbars, the oxygen atoms of which are phenoxide-Oof each of the two independent ligands. The lithium atoms are alternately four- and five-coordinate, the fourth coordination site of the first being occupied by the water molecule oxygen atom, while the fourth and fifth sites of the second are occupied by the cis-2-nitro oxygen atoms of the two ligands