Crystallographic coincidence of two bridging species in a dinuclear Co^IIIethynylbenzene complex

Abstract

Key indicators: single-crystal X-ray study; T = 120 K; mean (C-C) = 0.002 Å; disorder in main residue; R factor = 0.037; wR factor = 0.097; data-to-parameter ratio = 25.8.In the title compound, trans,trans-[-(m-phenylene)bis-(ethyne-1,2-diyl)]bis [chlorido(1,4,8,11-tetraazacyclotetradecane)

Copper(ii) complexes of N-propargyl cyclam ligands reveal a range of coordination modes and colours, and unexpected reactivity

“…Following chelation of a metal ion, a cyclam complex which exhibits a nominally square planar arrangement of nitrogen donors will adopt one of five configurations according to the spatial orientations of the backbone amine substituents: RSRS, RRRS, SSRR, RSSR and RRRR, respectively termed trans-I to trans-V. 34 The cyclam fragment [Cu( 6)] 2+ adopts the preferred trans-III configuration, with adjacent N-alkyl substituents (R-N-(CH2)3-N-R) displaced from the Cu-N plane. In spite of the tendency for similar complexes to exhibit metal-alkyne coordination, [35][36][37] no such interaction is observed here between the N-propargyl group (C11-C13) and the metal centre. As is the case with [Cu( 6)] 2+ , the single crystal structure of the [Cu( 7)] 2+ complex dication lacks propargyl substituent coordination to the metal centre (Figure 4 and SI Figure SX2).…”

Copper(II) Complexes of N-Propargyl Cyclam Ligands Reveal a Range of Coordination Modes and Colours, and Unexpected Reactivity

“…the Cu-N plane. In spite of the tendency for similar complexes to exhibit metal-alkyne coordination, [35][36][37] no such interaction is observed here between the N-propargyl group (C11-C13) and the metal centre. As is the case with [Cu(6)] 2+ , the single crystal structure of the [Cu 7] 2+ complex dication lacks propargyl substituent coordination to the metal centre (Figure 4 and SI Figure SX2).…”

Improving Redox Reversibility and Intermetallic Coupling of Co(III) Alkynyls through Tuning of Frontier Orbitals

“…30−33 With the desire to use more earth-abundant elements and cost-efficient resources, our recent efforts have focused on cyclam complexes of 3d transition metals (cyclam = 1,4,8,11tetraazacyclotetradecane). Our work, 34,35 along with those from the laboratories of Shores, 36,37 Nishijo, 38−42 and Wagenknecht, 43−48 has significantly expanded the scope of this previously underexplored field. While previous work on dicobalt species bridged by oligoynes revealed the structural features similar to highly delocalized Ru 2 compounds, their voltammetric responses were not ideal.…”