Research paper Homochiral zinc benzene-1,3,5-tricarboxylate coordination networks with a chiral nitrogen ligand or template: Spontaneous resolution of a twofold interpenetrated 2D sql (4,4) network and formation of enantiopure 3D sra (SrAl 2 ) networks Anas Tahli a,b , Anne-Christine Chamayou c , Ümit Köc a , Robin Brückner c , Reda F.M. Elshaarawy a,d , Christian Heering a , Christoph Janiak a,⇑ a Institut für Anorganische Chemie und Strukturchemie, Heinrich-Heine Universität Düsseldorf, Universitätsstr. 1, D-40225 Düsseldorf, Germany b Faculty of Science, Al-Furat University, Deir Ezzor, Syria c Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg im Breisgau, Germany d Faculty of Science, Suez University, Suez, Egypt article info Article history: Received 24 February 2016 Received in revised form 10 May 2016 Accepted 18 May 2016 Available online 27 May 2016 Keywords: Homochiral Coordination polymer Interpenetration Spontaneous resolution sql network sra network abstract A pair of homochiral enantiomorphic two-fold interpenetrated, mixed-ligand coordination polymers (CPs), 2D-{[Zn(l-Hbtc)(l-R-btrip)]H 2 O} n 1 and 2D-{[Zn(l-Hbtc)(l-S-btrip)]H 2 O} n 2, were found in a racemic conglomerate in space group P2 1 2 1 2 1 with enantiomorphous crystals by spontaneous resolution (H 3 btc = benzene-1,3,5-tricarboxylic acid, trimesic acid). The racemic ligand 1,2-bis(1,2,4-triazol-4-yl) propane (rac- or R,S-btrip) spontaneously resolves upon coordination to Zn(II) and crystallization from Zn(NO 3 ) 2 6H 2 O for 1 or ZnBr 2 for 2, in presence of the trimesic acid (H 3 btc) under hydrothermal condi- tions. Single-crystal analysis of 1 and 2 revealed a chiral two-dimensional sql (4,4) network based on the interconnection of {Zn(Hbtc)} and {Zn(btrip)} chains at the Zn atom. Each 2D sql network is 2-fold inter- penetrated by a symmetry related net. The interpenetration appears controlled by triazole–C–HN hydrogen bonds. When the enantiopure Schiff base 2-((E)-(1-(4-methoxyphenyl)ethylamino)methyl) phenol (N-(1-(4-methoxyphenyl)ethyl)salicylaldimine) was reacted with ZnSO 4 and H 3 btc in water/ methanol the imine C@N bond hydrolyzed retro-synthetically to the aldehyde and the amine which was protonated to the ammonium cation. The in-situ formed enantiopure (R) or (S)-1-(4-methoxyphe- nyl)ethylammonium cation was incorporated as a template in the crystallization of the anionic 3D-net- work {bis(benzene-1,3,5-tricarboxylato-j 4 O:O 0 :O 00 :O 000 0 )dizinc(II)}, {[Zn 2 (l 4 -btc) 2 ] 2 } n in the chiral compounds {[(R)- or (S)-4-CH 3 OC 6 H 4 CH(CH 3 )NH 3 ] 2 [Zn 2 (l 4 -btc) 2 ]2H 2 O} n (3 or 4, respectively). The 3D- network exhibited sra (SrAl 2 , zeolite ABW) topology. The ammonium cations are positioned by charge-assisted N–H (+)  () O (carboxylato) H-bonds and charge-assisted p-stacking in the anionic framework. Ó 2016 Elsevier B.V. All rights reserved. 1. Introduction The assembly of organic molecules and metal-cluster secondary building units (SBUs) to (porous) coordination polymeric materials, often called metal–organic frameworks (MOFs) is of continuous interest due to their potential applications in gas sorption and stor- age [1,2], gas separation [3,4,5], sensing [6], catalysis [7], lumines- cence [8], non-linear optics (NLO, frequency doubling) [9] and low temperature heating and cooling through reversible water de- and adsorption [10]. Homochiral MOFs have gained growing interest for their poten- tial applications in chiral separation, asymmetrical catalysis, opti- cal materials and magnetisms [11–14]. Chiral MOFs can be prepared from achiral starting materials if the framework grows in a chiral space group as a racemic conglomerate by spontaneous resolution [14] or upon seeding with M- or P-crystals as single-col- ony homochiral M- or P-crystals only [15]. Also, MOF chirality can be induced and the enantiomer controlled by a chiral templating agent which itself does not become part of the final structure [16]. A third and often the most effective option is to directly grow http://dx.doi.org/10.1016/j.ica.2016.05.042 0020-1693/Ó 2016 Elsevier B.V. All rights reserved. ⇑ Corresponding author. E-mail addresses: anne.chamayou@yahoo.fr (A.-C. Chamayou), janiak@hhu.de (C. Janiak). Inorganica Chimica Acta 450 (2016) 190–201 Contents lists available at ScienceDirect Inorganica Chimica Acta journal homepage: www.elsevier.com/locate/ica