
TY  - JOUR
A1  - Harrowfield, Jack M. 
A1  - Sharma, Raj Pal 
A1  - Skelton, Brian W. 
A1  - White, Allan H. 
T1  - Structural Systematics of 2/4-Nitrophenoxide Complexes of Closed-Shell Metal Ions. VII  Acid Salts of the 4-Nitrophenoxides of Group 2
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1998
VL  - 51
IS  - 8
SP  - 785
EP  - 794
KW  - 
UR  - https://doi.org/10.1071/C97104 
N2  - Room-temperature single-crystal X-ray structure determinations are recorded for a number of Group 2 4-nitrophenoxide acid salts, variously hydrated M(4-np)2.x(4-npH).yH2O. Ca(4-np)2.2(4-npH).8H2O is monoclinic, P 21/n, a 30&#183;52(1), b 10&#183;027(1), c 23&#183;65(2) &#197;, &#946; 116&#183;3(5)&#176;, Z = 8, conventional R on &#124;F&#124; being 0&#183;058 for No 5092 independent &#8216;observed&#8217; (I &#62; 3s(I)) reflections. Sr(4-np)2.2(4-npH).8H2O, based on a subcell of the former, is monoclinic, P 21/c, a 15&#183;576(5), b10&#183;081(6), c 24&#183;20(2) &#197;, &#946; 117&#183;99(5)&#176; , Z = 4, R 0&#183;054 for No 2908. Ba(4-np)2.2(4-npH).4H2O is orthorhombic, Fdd2, a 28&#183;01(1), b 19&#183;90(1), c 10&#183;692(7)&#197;, Z = 8, R 0&#183;028 for No 1967. The strontium array (and that of the calcium salt developed from it) may be represented as &#91;(H2O)6Sr(4-npH.4-np)&#93; (4-npH.4-np), a neutral ligand being unsymmetrically chelated to the strontium through the nitro group, with a quasi-parallel counter ion hydrogen-bonded to it by phenoxide confrontation. The other two 4-np residues make up a similar phenoxide-confronting pair (4-npH.4-np), the hydrogen being more intimately associated with one moiety. The barium salt is also an interesting array: the 10-coordinate barium lies on a crystallographic 2 axis, in an environment of two pairs of symmetry-related nitro-chelating ligand anions, and a pair of nitro-O coordinating neutral 4-npH ligands; the whole &#91;(H2O)4Ba(4-np)2(4-npH)2&#93; array may be envisaged as a single neutral (super)molecule. Hydrogen bonds between confronting phenoxides of the neutral 4-npH components of the parent and the 4-np- components of neighbouring molecules link the whole into a three-dimensional array. 
ER  -

