ResultsCrystal structures of [Cd(MIMZ)4](BPh4)2·2MeCN,2, and [Cd(MIMZ)4](CF3SO3)2,3Both crystals are triclinic, with space-groupP1&cmb.macr;, and one formula unit in the asymmetric unit. Crystallographic details are provided inTable 1.Crystal data for2and3Parameter23Clickherefor full crystallographic data (CCDC reference numbers 176610 and 176611).FormulaC16H32CdN8S4·(C24H20B)2·(C2H3N)2C16H32CdN8S4·(CF3O3S)2M1297.7875.3Crystal systemTriclinicTriclinicSpace groupP1&cmb.macr;P1&cmb.macr;a/Å10.300(1)8.8454(4)b/Å14.444(1)12.9065(5)c/Å24.388(2)15.5357(6)α/°80.53(1)82.571(2)β/°79.72(1)78.288(2)γ/°71.38(1)78.584(2)V/Å33360.6(5)1695.0(1)Z22Dc/g cm−31.281.72μ(Mo)/mm−10.491.092&thetas;max/°5052.7Crystal decay (%)NoneNoneMin. transmission factorN/a0.42Max. transmission factorN/a0.82Unique reflections11 1316635Observed reflections67615649Rmerge0.0460.049R0.0460.043Rw0.0610.120Molecular geometry of the cations in2and3We describe first the molecular structure of the [Cd(MIMZ)4]2+complex and the conformations of its rings, then the overall crystal packing, followed by details of the supramolecular motifs in each crystal.The metrics of the cadmium coordination are given inTable 2. In both structures there is some distortion from regular tetrahedral geometry, in terms of both Cd–S distances and angles at Cd.Distances (Å) and angles (°) in the [Cd(MIMZ)4]2+complex 23For2, S1–S4 correspond to S1A–S1D in the crystallographic information, whereas for3, they correspond to S11–S41.Cd–S12.516(1)2.5339(9)Cd–S22.563(1)2.5397(9)Cd–S32.526(1)2.5206(9)Cd–S42.528(1)2.5180(8) S1–Cd–S2109.4(1)112.42(3)S1–Cd–S3110.5(1)108.17(3)S1–Cd–S4114.3(1)111.12(3)S2–Cd–S3122.0(1)106.80(3)S2–Cd–S495.6(1)100.86(3)S3–Cd–S4104.3(1)117.32(3)There are many degrees of freedom providing the conformation of the [Cd(MIMZ)4]2+complex. In both2and3, the conformation is unusual in that two of the MIMZ rings are oriented so that they are approximately parallel and able to form an offset face-to-face (OFF) interaction (Fig. 1). Inspection of similar molecules in the CSD shows that this conformation is uncommon for tetrahedrally coordinated centres with S–R ligands (R = aryl or heterocyclic group). We believe that electrostatic interactions stabilise this conformation.Fig. 2shows the atom partial charges for the coordinated MIMZ ligand in2(as calculated by the QEq procedure8) and the juxtaposition of opposite charges.For2it is the rings on S1 and S4 inTable 2which are near parallel, whereas for3it is those on S2 and S3. There appears to be no correlation between the distortions from regular geometry at Cd and the conformations of the rings.Structure of the [Cd(MIMZ)4]2+cation in2(a) and3(b). In each, there are two MIMZ ligands in an offset-face-to-face conformation. The extent of the ring overlap in the pair of parallel rings is less in3than in2, and the disposition of the remaining rings, and the overall shape of the cation, is quite different in the two structures.Atom partial charges for the two MIMZ ligands involved in the offset-face-to-face intramolecular interaction in [Cd(MIMZ)4]2+, calculated by the QEq method. In (a) charges are for the cation in2and are marked in blue for hydrogen atoms. Note that for pairs of equivalent hydrogen atoms, those lying between the rings have a slightly lower charge. Charges for the cation in3are similar. The view in (b) is projected normal to the rings in2, and shows the juxtaposition of the appreciably oppositely charged C2 and N3 atoms. View (c) is the corresponding view for3. Note that the overlap is not as extensive, but there is still juxtaposition of positive and negative regions.Crystal packing in [Cd(MIMZ)4](BPh4)2·2MeCN,2Crystal packing of2is shown inFig. 3. The arrangement of species in the unit cell is shown, and the locations of the principal supramolecular motifs are identified. Hydrogen bonding of the type N–H⋯N links the cations and N of the acetonitrile solvent. There are two independent anions, each of which forms the double flipper, and all four crystallographically distinct Ph2pairs forming double flippers are engaged in the identified motifs. There is a weak OFF between pairs of phenyl rings around the centre of inversion at (0,0,0), but the principal crystal packing stabilisation in2derives from the three types of motifs identified inFig. 3, and described next.Projection down the shortest axis,a, of the lattice of [Cd(MIMZ)4](BPh4)2·2MeCN,2: Cd is black, S is yellow, N is dark blue, B is red. Anion carbon is orange, cation carbon is green and solvent carbon is blue. Hydrogen bonding is marked as blue and white candystripes. The double flipper conformations of the two independent BPh4–ions are readily apparent. The ellipses identify the locations of the three key motif types. The blue ellipse surrounds a single cation and a pair of crystallographically different anions. The black ellipses surround centrosymmetric pairs of solvent molecules and pairs of anions. Note that all four of the double flipper Ph2pairs are engaged in the identified motifs.The BPh4–⋯[Cd(MIMZ)4]2+⋯Ph4B–box in2Fig. 4shows how the OFF pair of MIMZ ligands in the cation of2are enclosed in a box constructed from two BPh4–flippers. Six rings are involved: each MIMZ ligand forms an additional OFF and an edge-to-face (EF) interaction with a Ph2flipper. This motif has no crystallographic symmetry, but has pseudo twofold symmetry.The favourable enclosure of the pair of MIMZ rings from [Cd(MIMZ)4]2+in2between a pair of Ph2flippers of BPh4–(C orange), forming the six-ring BPh4–⋯[Cd(MIMZ)4]2+⋯Ph4B–box motif. Each MIMZ participates in two offset-face-to-face and one edge-to-face interaction. Click image orhereto access a 3D representation.The BPh4–⋯(CH3CN)2⋯Ph4B–boxes in2There are two different instances within the crystal structure2of a similar box surrounding a pair of MeCN molecules, as shown inFig. 5. Both of these arrangements are centrosymmetric. In both cases, the methyl ends of the solvent molecules are adjacent, and make C–H⋯phenyl contacts with the walls of the box. The occurrence of two independent and similar box motifs in this crystal indicates stabilisation, but, as considered below in the discussion, there appear to be no other known instances of this motif.The two independent centrosymmetric BPh4–⋯(CH3CN)2⋯Ph4B–boxes in2: hydrogen atoms on CH3CN are not shown. (a) The motif at crystallographic sites c (0,1/2,0). Click image orhereto access a 3D representation. (b) The motif at crystallographic sites f (1/2,0,1/2). Click image orhereto access a 3D representation. The separation of the methyl carbon atoms is 3.61 Å in (a) and 3.35 Å in (b); the B⋯B distances are 9.55 (a) and 9.67 Å (b).Crystal packing in [Cd(MIMZ)4](CF3SO3)2,3These crystals, solvent-free from a mixture of acetonitrile and diethyl ether, manifest a crystal packing where double columns of cations parallel toa(centred atb= 1/2) are separated by the triflate anions. There is one edge-to-face interaction between complex cations (EF inFig. 6) of two different columns. In addition, there is hydrogen bonding between the N–H of the cation and triflate O (marked with a blue and white candystripe onFig. 6) which also links two columns of cations in thebdirection.Crystal packing in [Cd(MIMZ)4](CF3SO3)2,3. Triflate molecules are coloured orange (CF3) and red (SO3). Ellipses surround the regions of interactions between columns: black for the EF interactions, and blue for the N–H⋯O hydrogen bonding.There are a number of other significant interactions in this structure. S⋯S and C(N)–H⋯S interactions (both intra- and inter-molecular) occur within the double columns of cations. These are shown inFig. 7.Double columns of cations alonga, atb= 1/2 viewed (a) along the column, and (b) orthogonal to the column. S⋯S interactions, which range in length from 3.4 to 4.0 Å are marked as orange and white candystripes, while C–H⋯S (3.2, 3.3 Å) and N–H⋯S (2.8 Å) are black and white.There are numerous C–H⋯O interactions between cations and the triflate anions. We will report on more extensive analysis of interactions with triflate at a later date.