Room-temperature single-crystal X-ray studies are recorded for
2-nitrophenoxide salts of Group 2 metals, variously hydrated
M(2-np)2.xH2O,
M = Mg, Ca, Sr; the structure of the barium analogue has been
previously recorded.
Mg(2-np)2.2H2O is monoclinic,
P21/a,
a 7·377(1), b
7·518(1), c 12·877(3) Å, β
106·58(2)°, Z = 2; conventional
R on |F| 0·13
for No 508 independent
‘observed’ (I >
3σ(I)) reflections.
Ca(2-np)2.H2O is monoclinic,
C2, a 25·92(1),
b 7·176(3), c
3·660(4) Å, β 93·66(5)°, Z
= 2, R 0·061 for
No 541.
M(2-np)2.4H2O, M = Ca, Sr,
are isomorphous, monoclinic,
C2/c, a
≈ 31·3, b ≈ 8·1,
c ≈ 12·8 Å, β 103°,
Z = 8; R was 0·056,
0·055 forNo 1988, 1744
respectively. The magnesium salt is a discrete molecular array disposed about
a crystallographic inversion centre with chelating phenoxide ligands:
trans-[Mg(2-np)2(OH2)2].
The calcium monohydrate salt is a novel one-dimensional polymer with a ...
Ca(µ-O)2Ca(µ-O)2Ca ...
spine, the ligand pairs chelating the calcium with
phenoxide-O additionally bridging. The seven-coordinate
calcium atoms lie on the crystallographic 2 axis with
the water molecule, also on that axis, making up a seven-coordinate
environment. The tetrahydrate is also a one-dimensional polymer with a similar
spine, the bridging oxygen atoms derivative of water molecules. A chelating
ligand and two further water molecules make up an eight-coordinate metal
environment, with the free anions interleaving stacks of coordinated anions up
c.