A. Del Pra

Isomorphous compounds [Nd(TDTD)1.5(pic)3] and [Er(TDTD)1.5(pic)3] (pic = picrate, TDTD = trans‐1,4‐dithiane S,S'‐dioxide)

The structures of two isomorphous and isostructural lanthanide derivatives, poly[tri(picrato-O 1 ,O 2 )neodymium-μ-(trans-1,4-dithione S,S-dioxide-S:S) 1.5 ], [Nd(C 6 H 2 N 3 O 7 ) 3 (C 4 H 8 O 2 S 2 ) 1.5 ], and poly[tri(picrato-O 1 ,O 2 )erbium-μ-(trans-1,4-dithiane S,S-dioxide-S:S) 1.5 ], [Er(C 6 H 2 N 3 O 7 ) 3 (C 4 H 8 O 2 S 2 ) 1.5 ] consist of nine-coordinate metal ions, linked to three bidentate picrate ligands, bound via the phenoxo O atom and one O atom of an adjacent nitro group, and to three O atoms of three TDTD ligands

Structure of 1H-indazole-3-carboxylic acid

C 8 H 6 N 2 O 2 , M r =162.15, monoclinic, P2 1 /n, a=10.402 (2), b=15.025 (3), c=9.467 (2) A, β=96.24 (3) o , V=1470.8 (5) A 3 , Z=8, D m (flotation in heptane/carbon tetrachloride)=1.45, D x =1.46 Mg m -3 , λ(Mo Kα)=0.71069 A, μ=0.102 mm -1 , F(000)=672, T=295 K, R=0.041 (wR=0.048) for the 2105 observed reflections with I≥2.5σ(I). In both molecules of the asymmetric unit the carboxy group prefers a near coplanar [4.8 (1) and 5.4 (1) o ] and transoid orientation with respect to the strictly planar heterocyclic ring

(S)-(−)-3-(4-Phenyl-1-piperazinyl)-1,2-propanediol N,N'-Dioxide

The piperazine ring of the title molecule, C 13 H 20 N 2 O 4 , assumes a chair conformation with the two N→O groups oriented trans-axially to each other. The O atoms of each molecule of the crystal are involved in an infinite three-dimensional O−H...O hydrogen-bond network, which is mainly responsible for the packing

Structure of ethyl 2-(3-methyl-1,2,4-oxadiazol-5-yl)-2-phenylhydrazonoethanoate

C 13 H 14 N 4 O 3 , M r =274.3, orthorhombic, Pna2 1 , a=19.048 (6), b=10.507 (4), c=6.691 (4) A, V=1339. 1 A 3 , Z=4, D m =1.36 (flotation), D x =1.360 Mg m -3 , λ(Mo Kα)=0.7107 A, μ=0.933 cm -1 , F(000)=576, T=298 K, R=0.0839, wR=0.0643 for 773 observed reflections. The whole molecule is approximately planar, which can be seen from the values of the torsion angles about the non-rigid bonds; the molecular dimensions are in agreement with those found in analogous compounds

Structures of the configurational isomers of 2,2'-bis(3-chlorophenyl)[3,3'-bi-1,3-thiazolidine]-4,4'-dione

PA, C18H14C12N20282, Mr=425.36, tri- clinic, P1 (after structure determination), a-- 11.232(2), b=10.465(2), c=8.386(2) A, a= 107-07 (3), fl = 83-63 (4), y = 98.90 (3) °, V= 928.7 (4)/~3, Z = 2, Dx = 1.521 g cm -3, ,~(Mo Ka) = 0.71069 A,/1, = 5.27 cm -~, F(000)= 436, room tem- perature. Final conventional R value is 0.033 (wR = 0.041) for 2716 diffractometer-measured intensities with I___ 3tr(l). The molecular structure is charac- terized by the different conformations of the two thiazolidine rings, one of which is an envelope, and by opposite chirality of the two asymmetric C atoms. In the crystal structure both the enantiomers 2S,2R and 2R,2S are present. PB, CI8HI4C12N20282, Mr = 425.36, orthorhombic, Pbcn, a=7.759(2), b= 19.625 (4), c = 12.504 (3) A, V= 1904.0 (6) A 3, Z = 4, Dx = 1.483 g cm -3, a(Mo Ka) = 0.71069 A, /1, = 5.14cm -I, F(000)= 872, room temperature. Final conventional R value is 0.049 (wR = 0.067) for 1334 diffractometer-measured intensities with I_> 3tr(l). Because the molecular structure has exact C2 sym- metry, the two phenyl rings are strictly parallel and the conformations (half chair) of the two thiazolidine rings are the same as well as the chirality of the two asymmetric C atoms. Nevertheless both enantiomers 2R,2R and 2S,2S are in the crystal.