
TY  - JOUR
A1  - Effend, y 
A1  - Engelhardt, LM 
A1  - Healy, PC 
A1  - Skelton, BW 
A1  - White, AH 
T1  - Lewis-Base Adducts of Group 11 Metal(I) Compounds. Synthesis and Structural Characterization of Some Halopyridin/triphenylphosphinesilver(I) Complexes: Some Space Group Revisions for Parts LII-LIV
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1991
VL  - 44
IS  - 11
SP  - 1585
EP  - 1590
KW  - 
UR  - https://doi.org/10.1071/CH9911585 
N2  - Redetermination of the room-temperature crystal structures of mononuclear chloro- and bromo-pyridinebis ( triphenylphosphine )silver(I) (previously described in space group P21/m) and di-&#956;-iodo-bis [(pyridine)( triphenylphosphine )silver(I)](previously described in space group C2/m), consequent upon the availability of crystals of improved quality, has permitted the reassignment of space groups as P21/a (with doubled a axis) and C2/c respectively, by virtue of the facilitated detection of weak superlattice reflections. Crystals of [ Cl,BrAg ( py )(PPh3)2] are monoclinic, P21/a, a &#8776; 19.6, b &#8776; 20.0, c &#8776; 9.1&#506;, &#946; &#8776; 97.5&#176;, Z = 4; the structures were refined to residuals of 0.034 and 0.040 for 2965 and 2315 'observed' reflections respectively. [(PPh3)( py )AgI2Ag( py )(PPh3)] is monoclinic, C2/c, a 27.145(6), b 14.548(3), c 11.316(4)&#506;, &#946; 94.83(2)&#176;, Z 4, refining to R 0.035 for 1892 'observed' reflections, and isomorphous with the [(PPh3)( py )CuX2Cu( py )(PPh3)] family. In spite of this reassignment, the previous descriptions of the AgX /N/P cores of the species are essentially unchanged, the previous residuals of the misassigned space group determinations being comparable with the present; the only non- trivial change lies in the fact that the disordered phenyl rings of the earlier work are now fully ordered. It now seems certain that the 'second polymorph' of [(PPh3)( py )CuBr2Cu( py )(PPh3)], recorded as being isomorphous with its C2/m silver iodide counterpart, is spurious and a consequence of the use of an inferior specimen. 
ER  -

