The phenomenon of conglomerate crystallization. Part 40: The crystallization behavior oftrans- Co(III) amines (+)546-trans-[Co(3,2,3-tet)(NO2)2]Cl·3H2O (I), (−)589 -trans-[Co(3,2,3-tet)Cl2]NO3 (II), and of (+)546-trans-[Co(3,2,3-tet)(NO2)2]NO3 (III)

Abstract

A racemic solution of (I) crystallizes as a conglomerate from which a crystal we selected was found to be (+) 2, . A total of 2305 data were collected over the range of 4 ~ _< 20 _ 55~ of these, 1724 (independent and with I >_ 3a(1)) were used in the structural analysis. Data were corrected for absorption (~t = 11.920 cm-I), and the relative transmission coefficients ranged from 0.8258 to 0.9565. Refinement was carded out for both lattice enantiomorphs, and at this stage the R(F) and R~.(F) residuals were, respectively, 0.0381 and 0.0479 for (+ + +) and 0.0448 and 0.0532 for (---). Thus, the former was selected as correct for our specimen, and the final cycle of refinement with the (++ +) model converged to R(F) and R,.(F) of 0.0315 and 0.0365. A racemic solution of (II) crystallizes as a conglomerate from which a crystal we selected was found to be 2,Cl2]N03 (II), CoCIzO3NsCsH22. It crystallizes in the enantiomorphic space groujp, P21 with lattice constants a = 6.395(2) ,~, b = 8.886(2) ,~., c = 13.185(2) :k, and/3 = 99.24(2)~ V = 739.59 ,~3 and d(calc. M.W. = 366.14, Z = 2) = 1.646 g cm -3. A total of 2912 data were collected over the range of 4 ~ _< 20 _< 64~ of these, 2147 (independent and with I >_ 3a(1)) were used in the structural analysis, Data were corrected for absorption (/z = 15.424 cm-I), and the relative transmission coefficients ranged from 0.9632 to 0.9985. Refinement was carded out for both lattice enantiomorphs, and the final R(F) and R,,.(F) residuals were, respectively, 0.0326 and 0.0328 for (+ + +) and 0.0347 and 0.0348 for (---). Thus, the (+ + +) was selected as correct for our specimen. A racemic solution of (III) crystallizes as a conglomerate from which a crystal we selected was found to be (+) 2, Bernal, Cetrullo, Cai, and Massoud correct for our specimen, and the final cycle of refinement with the (---) model converged to R(F) and Rw(F) of 0.0436 and 0.0421. For all three compounds, the six-membered rings are chairs; the secondary nitrogens are chiral centers, and the five-membered rings are ordered and conformationally dissymmetric, as expected. Coincidentally, in (I), (II), and (III) the central rings are right-handed helices with ~t(+50.0~ ~5(+53.3~ and t5(+48.3~ respectively. Thus, the secondary nitrogens of all three cations are (R), rendering the cations chiral. The incidence of conglomerate crystallization in trans coordination compounds is rare, and those known are asymmetrically substituted (see Ref. 4 for the four known cases). Thus, the incidence of such crystallization mode in a new series of [trans-Co(amine ligands)X2] § cations bearing symmetrical pairs of trans ligands was an unexpected and welcomed event. In all three cases, the counteranions are bonded to the hydrogens of the terminal --NH2 moieties, thus forming an overall entity which resembles a macrocycle. In fact, parallels between the crystallization behavior of our compounds and that of macrocycles bearing related fragments is discussed. Finally, in the three compounds, homochiral cations are linked into infin...

Crystal Engineering Using Bisphenols and Trisphenols. Complexes with Hexamethylenetetramine (HMTA): Strings, Multiple Helices and Chains-of-Rings in the Crystal Structures of the Adducts of HTMA with 4,4'-Thiodiphenol (1/1), 4,4'-Sulfonyldiphenol (1/1), 4,4'-Isopropylidenediphenol (1/1), 1,1,1-Tris(4-hydroxyphenyl)ethane (1/2) and 1,3,5-Trihydroxybenzene (2/3)

“…Hence, all the triple helices are interlinked, although there are no hydrogen-bonding interactions between the individual strands within a triple helix. Although both components are achiral, their interaction produces helices and in space group P2t2121 all the helices in a given crystal are of the same hand; the formation of this chiral structure may be regarded as an example of conglomerate crystallization (Bernal, Cetrullo, Cai & Massoud, 1995). The one-dimensional structure found here, with three identical but unconnected intertwined helices, has some resemblance to the three-dimensional structures found for methanetetraacetic acid (Ermer & Eling, 1988), adamantane tetracarboxylic acid (Ermer, 1988) and trimesic acid (Duchamp & Marsh, 1969), where there are three, five and six independent interpenetrating networks, respectively.…”

1-Ferrocenyl-2-phenylethanedione

“…The conformation found for (I) corresponds to molecular point group C~, so that the molecules are chiral in the solid state, and all have the same handedness in P212121; in the crystal chosen for study, the molecules have the S configuration. In solution, however, the NMR spectra indicate that R/S interconversion is fast at room temperature, so that crystallization in P2~2121 represents a case of spontaneous resolution, or 'conglomerate crystallization' [Fe(C5H5) , 1985;Bernal, Cetrullo, Cai & Massoud, 1995). The intramolecular bond lengths and angles are unexceptional; the central C--C distance, 1.529 (5)~,, is very similar to the lengths found in butane-2,3-dione [gas-phase 1.524(3)A (Danielson & Hedberg, 1979), solid state 1.540 (6)A (Eriks et al, 1983)] and in benzil [trigonal high-temperature phase 1.523 (6) .~, monoclinic low-temperature phase 1.526 (13)-1.549 (16) ,~,, mean 1.536 A (More et al, 1987)].…”

1,1'-Ferrocenediylbis(2-phenylethanedione): a Three-Dimensional Network Generated by Short C—H.O Hydrogen Bonds

“…The conformation found for (I) has (?2 symmetry, so that in the solid state the mop ecules are chiral. In solution, the NMR spectra indicate that R,--->S interconversion is fast at room temperature, so that crystallization in the P3~21 space group represents a case of spontaneous resolution or 'conglomerate crystallization' (Bemal, 1985;Bernal, Cetrullo, Cai & Massoud, 1995).…”