Non-covalent intramolecular interactions through ligand-design promoting efficient photoluminescence from transition metal complexes

2020 ◽  
Vol 405 ◽  
pp. 213094 ◽  
Author(s):  
Igor O. Koshevoy ◽  
Maren Krause ◽  
Axel Klein
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Ligand Design ◽  
Intramolecular Interactions

scholarly journals A New Twist on an ‘Old’ Ligand: A [Mn16] Double Square Wheel and a [Mn10] Contorted Wheel

2020 ◽  
Author(s):  
Euan Brechin ◽  
Constantinos J. Milios ◽  
Thomais Tziotzi ◽  
Marco Coletta ◽  
Mark Gray ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Direct Current ◽  
Coordination Compounds ◽  
Exchange Interactions ◽  
Ligand Design ◽  
Jahn Teller

Ligand design remains key to the synthesis of coordination compounds possessing specific topologies, nuclearities and symmetries that direct targeted physical properties. N,O-chelates based on ethanolamine have been particularly prolific in constructing a variety of paramagnetic 3d transition metal complexes with fascinating magnetic properties. Here, we show that combining three ethanolamine moieties within the same organic framework in the form of the ligand 1,3,5-tri(2-hydroxyethyl)-1,3,5-triazacyclohexane (LH3) leads to the formation of two highly unusual Mn wheels. Reaction of Mn(NO3)2·6H2O with LH3 in basic methanolic solutions leads to the formation of [MnIII 12MnII 4(µ3-O)6(µ-OH)4(µ3-OMe)2(µOMe)2(L)4(LH)2(H2O)10](NO3)6(OH)2 (1) and [MnIII 10(µ3-O)4(µ-OH)4(µ-OMe)4(L)4(H2O)4](NO3)2 (2); the only difference in the synthesis being the ratio of metal:ligand employed. The structure of the former describes two offset [MnIII 6MnII 2] square wheels, linked through a common centre, and the latter a single [MnIII 10] wheel twisted at its centre, such that the top half is orientated perpendicular to the bottom half. In both cases the L 3- /LH2- ligands dictate the orientation of the Jahn-Teller axes of the MnIII ions which lie perpendicular to the triazacyclohexane plane. Direct current magnetic susceptibility and magnetisation data reveal the presence of competing exchange interactions in 1 and strong antiferromagnetic interactions in 2. Given the simplicity of the reactions employed and the paucity of previous work, the formation of these two compounds suggests that LH3 will prove to be a profitable ligand for the synthesis of a multitude of novel 3d transition metal complexes

Optisch aktive Übergangsmetall-Komplexe, 122. Synthese von Palladium(II)-Schiff-Base-Komplexen -intramolekulare Wechselwirkungen / Optically Active Transition Metal Complexes, 122. Synthesis of Palladium (II) Complexes with Schiff Base Ligands -Intramolecular Interactions

2000 ◽  
Vol 55 (2) ◽  
pp. 145-154 ◽  
Author(s):  
Henri Brunner ◽  
Markus Niemetz ◽  
Manfred Zabel
Keyword(s):  
Crystal Structure ◽  
Schiff Base ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Optically Active ◽  
Intramolecular Interactions ◽  
Schiff Base Ligands ◽  
Enantiomerically Pure ◽  
Active Transition

Abstract Imines of salicylaldehyde and 2,6-diformyl-p-cresol have been used as ligands in palladium (II) complexes. Enantiomerically pure ligands give enantiomerically pure complexes, racemic ligands give racemates and meso-forms. Differences between the respective isomers of the ligands within the complexes and between the diastereomers of the complexes were investigated. Crystal structure analyses established the trans configuration at the metal center.

scholarly journals Three transition-metal complexes with the macrocyclic ligandmeso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (L): [Cu(ClO4)2(L)], [Zn(NO3)2(L)] and [CuCl(L)(H2O)]Cl

2013 ◽  
Vol 69 (8) ◽  
pp. 862-867
Author(s):  
Sabina Yasmin ◽  
Sebastián Suarez ◽  
Fabio Doctorovich ◽  
Tapashi G. Roy ◽  
Ricardo Baggio
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Three Dimensional ◽  
Molecular Shape ◽  
Intramolecular Interactions ◽  
Strong Hydrogen Bond ◽  
Axial Ligands ◽  
Dimensional Network ◽  
Significant Difference

The three transition-metal complexes, (meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-κ4N)bis(perchlorato-κO)copper(II), [Cu(ClO4)2(C18H40N4)], (I), (meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-κ4N)bis(nitrato-κO)zinc(II), [Zn(NO3)2(C18H40N4)], (II), and aquachlorido(meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-κ4N)copper(II) chloride, [CuCl(C18H40N4)(H2O)]Cl, (III), are described. The molecules display a very similarly distorted 4+2 octahedral environment for the cation [located at an inversion centre in (I) and (II)], defined by the macrocycle N4group in the equatorial sites and two further ligands intrans-axial positions [two O–ClO3ligands in (I), two O–NO2ligands in (II) and one chloride and one aqua ligand in (III)]. The most significant difference in molecular shape resides in these axial ligands, the effect of which on the intra- and intermolecular hydrogen bonding is discussed. In the case of (I), all strong hydrogen-bond donors are saturated in intramolecular interactions, while weak intermolecular C—H...O contacts result in a three-dimensional network. In (II) and (III), instead, there are N—H and O—H donors left over for intermolecular interactions, giving rise to the formation of strongly linked but weakly interacting chains.

scholarly journals A New Twist on an ‘Old’ Ligand: A [Mn16] Double Square Wheel and a [Mn10] Contorted Wheel

2020 ◽  
Author(s):  
Euan Brechin ◽  
Constantinos J. Milios ◽  
Thomais Tziotzi ◽  
Marco Coletta ◽  
Mark Gray ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Direct Current ◽  
Coordination Compounds ◽  
Exchange Interactions ◽  
Ligand Design ◽  
Jahn Teller

Ligand design remains key to the synthesis of coordination compounds possessing specific topologies, nuclearities and symmetries that direct targeted physical properties. N,O-chelates based on ethanolamine have been particularly prolific in constructing a variety of paramagnetic 3d transition metal complexes with fascinating magnetic properties. Here, we show that combining three ethanolamine moieties within the same organic framework in the form of the ligand 1,3,5-tri(2-hydroxyethyl)-1,3,5-triazacyclohexane (LH3) leads to the formation of two highly unusual Mn wheels. Reaction of Mn(NO3)2·6H2O with LH3 in basic methanolic solutions leads to the formation of [MnIII 12MnII 4(µ3-O)6(µ-OH)4(µ3-OMe)2(µOMe)2(L)4(LH)2(H2O)10](NO3)6(OH)2 (1) and [MnIII 10(µ3-O)4(µ-OH)4(µ-OMe)4(L)4(H2O)4](NO3)2 (2); the only difference in the synthesis being the ratio of metal:ligand employed. The structure of the former describes two offset [MnIII 6MnII 2] square wheels, linked through a common centre, and the latter a single [MnIII 10] wheel twisted at its centre, such that the top half is orientated perpendicular to the bottom half. In both cases the L 3- /LH2- ligands dictate the orientation of the Jahn-Teller axes of the MnIII ions which lie perpendicular to the triazacyclohexane plane. Direct current magnetic susceptibility and magnetisation data reveal the presence of competing exchange interactions in 1 and strong antiferromagnetic interactions in 2. Given the simplicity of the reactions employed and the paucity of previous work, the formation of these two compounds suggests that LH3 will prove to be a profitable ligand for the synthesis of a multitude of novel 3d transition metal complexes

scholarly journals 1‐Amino‐5‐methyltetrazole in Energetic 3 d Transition Metal Complexes – Ligand Design for Future Primary Explosives

2021 ◽  
Vol 46 (2) ◽  
pp. 207-213
Author(s):  
Maximilian H. H. Wurzenberger ◽  
Michael S. Gruhne ◽  
Marcus Lommel ◽  
Jörg Stierstorfer
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Ligand Design

Mechanochemical changes on cyclometalated Ir(iii) acyclic carbene complexes – design and tuning of luminescent mechanochromic transition metal complexes

2020 ◽  
Vol 7 (3) ◽  
pp. 786-794 ◽  
Author(s):  
Jingqi Han ◽  
Kin-Man Tang ◽  
Shun-Cheung Cheng ◽  
Chi-On Ng ◽  
Yuen-Kiu Chun ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Carbene Complexes ◽  
New Class

A new class of luminescent cyclometalated Ir(iii) complexes with readily tunable mechanochromic properties derived from the mechanically induced trans-to-cis isomerization have been developed.

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