Controlled SBU Approaches to Isoreticular Metal‐Organic Framework Ruthenium‐Analogues of HKUST‐1

Abstract A controlled secondary building unit approach (CSA) was employed to obtain a series of ruthenium metal‐organic frameworks (MOFs) of the general formula Ru 3 (BTC) 2 X x · G g (BTC = 1, 3, 5‐benzenetricarboxylate; X = counter‐anion, G = guest molecules) which are structural analogues of M 3 (BTC) 2 (M = Cu, Zn, Ni, Cr, Mo). The compounds Ru 2 (OOCR) 4 X and Ru 2 (OOCCH 3) 4 Y were varied as Ru sources for CSA; namely strong coordinating X (Cl –) and weakly coordinating Y (BF 4 – or BPh 4 –) as well as the alkyl groups at the carboxylate ligand R = CH 3 or C (CH 3) 3 were utilized. Four phase‐pure Ru‐MOFs were obtained: Ru 3 (BTC) 2 Cl 0. 5 (OH) · (AcOH) 1. 5 (1), Ru 3 (BTC) 2 Cl 1. 2 (OH) 0. 3 · (H 3 BTC) 0. 15 (AcOH) 2. 4 (PivOH) 0. 45 (2), Ru 3 (BTC) 2 F 0. 5 (OH) · (AcOH) 1. 0 (3) and Ru 3 (BTC) 2 (OH) 1. 5 · (H 3 BTC) 0. 5 · (AcOH) 1. 4 (4) AcOH = CH 3 COOH, PivOH = (CH 3) 3 CCOOH. The series of characterization data support the analytical composition and isostructural nature of 1 – 4, i. e. powder X‐ray diffraction (PXRD), IR‐ and 1 H‐NMR spectroscopy, thermal gravimetric analysis (TGA) and N 2 sorption were employed. The valence state of the Ru‐sites were studied by X‐ray absorption spectroscopy (XAS). The chosen precursors for CSA and optimized synthesis, work‐up and activation protocols allowed improvement of the overall crystallinity, purity (i. e. , residual solvent molecules) and surface area of the Ru‐MOF materials.