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 Transition metal complexes with thiosemicarbazide-based ligands. Part 51. Square-planer nickel(II)complex with acetylacetone bis(S-n-propylisothiosemicarbazone)(L).Crystal and molecular structure of [

2006 ◽  
Vol 71 (6) ◽  
pp. 593-604 ◽  
Author(s):  
Vukadin Leovac ◽  
Vladimir Divjakovic ◽  
Valerija Cesljevic ◽  
Milena Rakocevic
Keyword(s):  
Molecular Structure ◽  
Structural Analysis ◽  
Transition Metal ◽  
Metal Complexes ◽  
Crystal Structures ◽  
Transition Metal Complexes ◽  
Crystal And Molecular Structure ◽  
Square Planar ◽  
Significant Difference ◽  
Template Reaction

The template reaction of a warm methanolic solution of Ni(OAc)2?4H2O S-n-propylisothiosemicarbazide hydroiodide and acetylacetone yielded the needle- like, brown, diamagnetic complex [Ni(L-H)]I?MeOH, and in the presence of an excess of NH 4NCS, brown, prismatic crystals of the complex [Ni(L-H)]NCS (1), both compounds involving the monoanionic form of the ligand, acetylacetone bis(S-n-propylisothiosemicarbazone), L. Slow recrystallization fromMeOH, EtOH, iPrOH and Me2CO gave the corresponding monosolvent complexes [Ni(L-H)]I?solvent, of which only those involving EtOH and iPrOH were suitable for structural analysis. The crystallographic parameters of [Ni(L-H)]I?EtOH (2) and [Ni(L-H)]I?iPrOH (3) are very similar to each other, showing their structures are isomorphic. The crystal structures of the title compounds consist of the independent ions: NCS-, or I-, and the chemically identical cation [Ni(L-H)]+, where L-H is the monoanion resulting from deprotonation of the acetylacetone moiety, a tetradentate N4 ligand forming a square-planar coordination around a Ni(II) ion. It was found that the isothiosemicarbazide fragment of the ligand has an imido form. The complex cations of the compounds [Ni(L-H)]NCS and [Ni(L-H)]I?EtOH exhibit significant difference only in the conformation of their propyl groups.

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.

Two new transition-metal complexes (TMCs)-templated three-dimensional supramolecular networks based on tungstovanadophosphates

2009 ◽  
Vol 182 (4) ◽  
pp. 690-697 ◽  
Author(s):  
Yu-Kun Lu ◽  
Xiao-Bing Cui ◽  
Ya-Bing Liu ◽  
Qing-Feng Yang ◽  
Shu-Yun Shi ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Three Dimensional ◽  
Supramolecular Networks

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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