The crystallization behavior of (±)-cis-α-[Co(dmtrien)(NO2)2]Cl· 0.5H2O 1 and (±)-cis-α-[Co(dmtrien)(NO2)2]I 2 † (dmtrien = 3,6-dimethyl-3,6-diazaoctane-1,8-diamine)

Tris(ethylenediamine-N,N′)cobalt(III) oxalate perchlorate dihydrate

“…In preceding papers (Bernal et al, 1995(Bernal et al, , 1996Cai et al, 1998), we reported a series of Co III ±amine complexes crystallized in enantiomorphic space groups whose asymmetric units are racemic pairs, a phenomenon de®ned as kryptoracemic crystallization. The kryptoracemic crystallization pathway is rather rarely adopted by coordination racemates (Bernal et al, 1995(Bernal et al, , 1996(Bernal et al, , 1997Cai et al, 1998;Rodriguez et al, 1996;Haupt & Huber, 1978), and is poorly documented and investigated.…”

“…In preceding papers (Bernal et al, 1995(Bernal et al, , 1996Cai et al, 1998), we reported a series of Co III ±amine complexes crystallized in enantiomorphic space groups whose asymmetric units are racemic pairs, a phenomenon de®ned as kryptoracemic crystallization. The kryptoracemic crystallization pathway is rather rarely adopted by coordination racemates (Bernal et al, 1995(Bernal et al, , 1996(Bernal et al, , 1997Cai et al, 1998;Rodriguez et al, 1996;Haupt & Huber, 1978), and is poorly documented and investigated. In order for a kryptoracemic crystallization mode to occur, the number of molecules in the unit cell, Z, must be an even multiple of the number of general positions of the space group and, while some atoms may share a non-crystallographic pseudo-inversion center, the degree to which they conform to such an inversion center varies for different sets of atoms.…”

Structural Aspects of Copper‐Mediated Atom Transfer Radical Polymerization with a Novel Tetradentate Bisguanidine Ligand

“…The ligand synthesis consists of three reaction steps. According to Cai et al the bisamine A1 was synthesized through the reaction of N ‐(2‐bromoethyl)phthalimide and N , N ′‐dimethylethylenediamine with 3, 6‐dimethyl‐1, 8‐diphthalimido‐3, 6‐diazaoctane as intermediate, which was hydrolyzed to the free bisamine with an excess of hydrochloric acid 15. The tetradentate bisguanidine ligand TMG 2 dmtrien ( L1 ) can be obtained through the reaction of the bisamine A1 with tetramethylchloroformamidinium chloride following the synthetic protocol of Kantlehner et al16 The overall synthesis is shown in Scheme .…”

“…Synthesis of TMG 2 dmtrien: The bisamine 3, 6‐dimethyl‐3, 6‐diazaoctan‐1, 8‐diamine (dmtrien) used for the ligand synthesis was prepared according to the procedure published by Cai et al15 To a solution of 3, 6‐dimethyl‐3, 6‐diazaoctan‐1, 8‐diamine · 4 HCl (40 mmol, 12.72 g) and triethylamine (240 mmol, 24.29 g) in dry MeCN (40 mL) a solution of the chloroformamidinium chloride (80 mmol. 13.86 g) in dry MeCN (40 mL) was added dropwise under vigorous stirring and ice cooling.…”

Diversity in a simple co-crystal: racemic and kryptoracemic behaviour

“…maintain a 1 : 1 ratio of enantiomers) are rare, with limited discussion found in the literature. [31][32][33][34][35][36][37] Morales & Fronczek coined the term ''kryptoracemate'' for these systems in 1996. 31 Fábián and Brock examined their occurrence amongst organic molecules by analysing the Cambridge Structural Database (CSD) in 2010; finding only 151 organic kryptoracemate structures at that time.…”