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1 DOI: /NCHEM.2259 An infinite chainmail of M 6 L 6 metallacycles featuring multiple Borromean links Flora L. Thorp-Greenwood, Alexander N. Kulak and Michaele J. Hardie * School of Chemistry, University of Leeds, UK General procedures Reagents and solvents were obtained from commercial sources and used as received. Evacuated samples were washed with diethyl ether and heated under vacuum for 8 hrs prior to elemental and other analyses. Elemental analyses were obtained on a Carlo Erba Elemental Analyser MOD 1106 instrument and performed by the service of the School of Chemistry at the University of Leeds. Infrared spectra were recorded on a Perkin-Elmer FTIR spectrometer and samples analysed as solids. The morphologies of the crystals were determined using SEM, where the glass cover slip supporting the crystals was mounted on an SEM stub using an adhesive carbon pad. Samples were viewing, without coating, with a FEI Nova 450 FEG-SEM operating at 1 kv using deceleration mode and CBS detector. For the micrographs shown in Figure 5d and 5e of the main text and Figure 12 of the supplementary information the sample was coated Pd/Pt coated to 3 nm thickness. Powder XRD patterns were recorded with Cu-K radiation using a Bruker D2 Phaser diffractometer. Thermogravimetric analysis was performed on a TA Instruments TGA Q50, with a heating rate of 10 C/min under an inert flow of nitrogen. Energy Dispersive X-ray analyses were performed on an Oxford Instruments INCA X-max80 EDS system coupled to a Jeol JSM LV scanning electron microscope with an accelerating voltage of 20 kv.. Mass spectrometry was performed on a Bruker MaXis Impact spectrometer where the sample was directly infused into the electrospray ionisation source in DMSO solvent. NATURE CHEMISTRY 1

2 Single crystal X-ray crystallography Additional comments on structure refinements The crystals were weakly diffracting and twinned and did not diffract to high angles which leads to a number of level A/B cifcheck alerts, responses to which are detailed below. PROBLEM: The value of sine(theta_max)/wavelength is less than RESPONSE: Crystals were weakly diffracting and did not diffract at high angles PROBLEM: The value of the weighted R factor is > 0.35 RESPONSE: Weak diffraction, large cell and twinning PROBLEM: Isotropic non-h Atoms in Main Residue(s)... RESPONSE: These are disordered groups of main fragment and terminal dimethylsulfoxide ligands the latter show thermal disorder that could not be adequately modelled 16 Report PROBLEM: Atom C44 has ADP max/min Ratio prolat RESPONSE: Part of a phenyl ring of the ligand scaffold PROBLEM: Large Non-Solvent H Uiso(max)/Uiso(min) Ratio RESPONSE: calculated Uiso on ligated dmso as above PROBLEM: VERY LARGE Solvent Accessible VOID(S) in Structure RESPONSE: Lattice contains unmodellable disordered solvent. SQUEEZE or similar routines were not employed due to twinning! Info PROBLEM: High wr2 Value (i.e. > 0.25)... RESPONSE: Weak diffraction, large cell and twinning 0.37 Report PROBLEM: Ratio of Maximum / Minimum Residual Density Report RESPONSE: Fourier ripple on Br7 PROBLEM: Large Reported Max. (Positive) Residual Density 5.76 ea-3 RESPONSE: Fourier ripple on Br7 NATURE CHEMISTRY 2

3 Additional Crystal Structure Diagrams of complex 1 Fig. 1. The asymmetric unit of [Cu 6 Br 10 (DMSO) 6 (H 2 O) 2 (L1) 6 ] 2Br n(dmso) 1 with disordered methyl and pyridyl groups shown. NATURE CHEMISTRY 3

4 Fig. 2. The six Borromean ring associations of a single metallacycle. The central image shows a metallacycle in purple with its six adjacent metallacycles (cf. Figure 3a in main text) and surrounding diagrams of trimers is an exploded view highlighting each individual Borromean ring association of the purple metallacycle. NATURE CHEMISTRY 4

5 Fig. 3. Detail from crystal structure showing approximate alignment of (iso-nicotinoyl)-cu-(isonicotinoyl) fragments of adjacent metallacycles. Cu Cu distances are ca. 4.4 Å indicating there is no interaction and rings are too far apart to indicate any - stacking. Fig. 4. Crystal packing diagram of 1 viewed down the c unit cell with hydrogen atoms excluded for the sake of clarity. Spheres show positions of lattice Br - (yellow).grey=c,red=o,blue=n,pink = S, yellow = Br, green = Cu. NATURE CHEMISTRY 5

6 Synchrotron data collection Data were collected on several different batches of samples using different X-ray sources. All crystals showed signs of twinning, and all batches gave consistent unit cell parameters. For example, data were collected at Diamond Light source on station I19 using synchrotron radiation ( = Å) however the data were of poor quality with both twinning and crystal decomposition in the beam. Hence only unit cell parameters and a diagram illustrating that the same gross structural features are obtained are presented (Figure 5). Crystal data: hexagonal, R 3, T = 100(1) K, a = (9), c = (2) Å, V = 72806(4) Å 3. Fig. 5. Asymmetric unit of gross structure obtained from synchrotron data collection (data does not refine to satisfactory residual values). Grey = C, red = O, blue = N, yellow = Br, green = Cu. NATURE CHEMISTRY 6

7 Powder XRD Simulated observed Solvated DMSO Fig. 6. Powder XRD of complex 1, as-synthesised (green), after evacuation (red) and simulated (blue). EDX SEM/EDX Data (Weight %) Sample Cu Br S L1 CuBr2 Run 01 L1 CuBr2 Run 02 L1 CuBr2 Run EDX analysis confirms that Cu and Br are the only heavy elements present in the complex, and lattice anion positions are Br -. Sulphur was also observed, suggesting that some DMSO solvent cannot be removed through evacuation, as the crystals had been washed with diethyl ether and were evacuated for 8 hours prior to EDX analysis to remove free solvent. NATURE CHEMISTRY 7

8 Thermogravimetric Analysis Fig. 7. TGA of complex [Cu 6 Br 10 (DMSO) 6 (H 2 O) 2 (L1) 6 ] 2Br n(dmso) % mass loss to ca. 190 C agrees with a value of n = 14 with the loss of all DMSO and coordinated water (21.9% calc). Void space within the structure calculated in the absence of any solvent (ie uncoordinated DMSO) > 2000 Å 3 per formula unit which is sufficient space to accommodate this number of solvent DMSO given molecular volume of a DMSO molecule is ca. 62 Å 3. NATURE CHEMISTRY 8

9 Crystal Morphology Fig. 8. A cluster of tubular needles of complex 1. Crystals were not observed to grow individually and were always part of a cluster such as this one. Fig. 9. FEG-SEM image of a broken up cluster of tubular needles. (Scale bar 500 m). NATURE CHEMISTRY 9

10 Fig. 10. FEG-SEM images of tubular crystals (Scale bars from top left clockwise 50 m, 30 m, 40 m, 20 m, 100 m, 50 m). NATURE CHEMISTRY 10

11 Fig. 11. FEG-SEM images highlighting tubular and thin needles with a solid appearance, and solid core of the broken up cluster. (Upper image scale bar = 300 m, left lower bar = 10 m, right lower bar = 200 m). NATURE CHEMISTRY 11

12 Fig. 12. FEG-SEM images of Pd/Pt coated needle clusters resulting from low concentration recrystallization. (Scale bars from top left clockwise 100 m, 50 m, 50 m, 5 m). NATURE CHEMISTRY 12