Synthetic and structural studies of mono-acetylide and unsymmetric bis-acetylide complexes based on CoIII-cyclam

Rise of Conjugated Poly-ynes and Poly(Metalla-ynes): From Design Through Synthesis to Structure-Property Relationships and Applications

Conjugated poly-ynes and poly(metalla-ynes) constitute an important class of new materials with potential application in various domains of science. The key factors responsible for the diverse usage of these materials is their intriguing and tunable chemical and photophysical properties. This review highlights fascinating advances made in the field of conjugated organic poly-ynes and poly(metalla-ynes) incorporating group 4-11 metals. This includes several important aspects of conjugated poly-ynes viz. synthetic protocols, bonding, electronic structure, nature of luminescence, structure-property relationships, diverse applications, and concluding remarks. Furthermore, we delineated the future directions and challenges in this particular area of research.

Crystal structures of 5,12-dimethyl-1,4,8,11-tetra-aza-cyclo-tetra-decane cobalt(III) mono-phenyl-acetyl-ide and bis-phenyl-acetyl-ide

Reported in this contribution are the synthesis and crystal structures of new mono- and bis-phenyl-acetyl-ides based on CoIII(DMC) (DMC is 5,12-dimethyl-1,4,8,11-tetra-aza-cyclo-tetra-deca-ne). Chlorido-(5,12-dimethyl-1,4,8,11-tetra-aza-cyclo-tetra-deca-ne)(phenyl-ethyn-yl)cobalt(III) chloride-aceto-nitrile-methanol (1/1/1), [Co(C8H5)Cl(C12H28N4)]Cl·CH3CN·CH3OH, 1, and (5,12-dimethyl-1,4,8,11-tetra-aza-cyclo-tetra-deca-ne)bis-(phenyl-ethyn-yl)cobalt(III) tri-fluoro-methane-sulfonate-di-chloro-methane (2/1), [Co(C8H5)2(C12H28N4)]2(CF3SO3)2·CH2Cl2, 2, were prepared under weak-base conditions in satisfactory yields. Single-crystal X-ray diffraction studies revealed that both 1 and 2 adopt a pseudo-octa-hedral symmetry in which the Cl-Co-C angles of 1 and C-Co-C of 2 range from 177.7 (2) to 178.0 (2)° and from 177.67 (9) to 179.67 (9)°, respectively. In both structures, the CoIII metal center is coordinated in the equatorial plane by four N atoms, in which the N-Co-N angles range from 85.6 (3) to 94.4 (3)°. The structure of 1 features two crystallographically independent mol-ecules in its triclinic cell (Z' = 2), which are related to each other by pseudo-monoclinic symmetry. The crystal investigated was twinned by a symmetry operator of the approximate double-volume C-centered cell (180° rotation around [201] of the actual triclinic cell), with a refined twin ratio of 0.798 (3) to 0.202 (3). Both methanol solvent mol-ecules in 1 are disordered, the major occupancy rates refined to 0.643 (16) and 0.357 (16). Compound 2 also contains two mol-ecules in the asymmetric unit, together with two tri-fluoro-methane-sulfonate anions [of which one is disordered; occupancy values of 0.503 (16) and 0.497 (16)] and a disordered di-chloro-methane [occupancy values of 0.545 (12) and 0.455 (12)].

Sustainable metal alkynyl chemistry: 3d metals and polyaza macrocyclic ligands

This article describes the recent development of sustainable metal-alkynyl chemistry based on the combination of 3d metals and polyaza macrocycles.