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首页> 外文期刊>Dalton transactions: An international journal of inorganic chemistry >Bowl adamanzanes-bicyclic tetraamines: syntheses and crystal structures of complexes with cobalt(III) and chelating coordinated oxo-anions
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Bowl adamanzanes-bicyclic tetraamines: syntheses and crystal structures of complexes with cobalt(III) and chelating coordinated oxo-anions

机译：碗金刚烷-双环四胺：与钴（III）和螯合配位氧阴离子的配合物的合成和晶体结构

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Seven cobalt(III) complexes of the macrobicyclic tetraamine ligand [2(4).3(1)]adamanzane ([2(4).3(1)]adz) are reported along with the crystal structure of six of these complexes. The solid state and solution structures are discussed, and a detailed assignment of the NMR spectra of the sulfato complex is provided. Four of the seven complexes contain a chelate coordinating oxo-anion ( sulfate, formiate, nitrate, carbonate). Equilibration of these species with the corresponding diaqua complex is generally slow. The rates of equilibration in 5 mol dm(-3) perchloric acid at 25 degrees C have been measured, yielding half lives of 20 min, 10 min and 3 h for the sulfato, formiato and carbonato species respectively. The corresponding reaction for the nitrato complex occurs with a half life of less than 3 min. The concentration acid dissociation constant for the Co([ 2(4).3(1)] adz)( HCO3)(2+) ion has been measured to K-a = 0.33 mol dm(-3) [ 25 degrees C, I = 2 mol dm(-3)] and K-a = 0.15 mol dm(-3) [ 25 degrees C, I = 5 mol dm(-3)]. The propensity for coordination of sulfate was found to be large enough for a quantitative conversion of the carbonato complex to the sulfato complex to occur in 3 mol dm(-3) triflic acid containing a small sulfate contamination. On this basis the decarboxylation in 5 mol dm(-3) triflic acid of the corresponding cobalt( III) carbonato complex of the larger macrobicyclic tetraamine ligand [ 3(5)] adz was reinvestigated and found to lead to the sulfato complex as well. The difference in exchange rate of the oxo-anion ligands for the cobalt( III) complexes of the two adamanzane ligands is discussed and attributed to fundamental differences in the molecular structure where an inverted con. guration of the secondary non-bridged amine groups is seen for the complexes of the larger [ 3(5)] adz ligand. The high af. nity for chelating coordination of oxo-anions for these two cobalt( III)-adamanzane-moieties is rationalised on basis of the N-Co-N angles. N-Co-N angles are compared for a series of adamanzane complexes, and the structural consequences are discussed.
机译：报道了大双环四胺配体[2（4）.3（1）]金刚烷（[2（4）.3（1）] adz）的七个钴（III）配合物以及其中六个配合物的晶体结构。讨论了固态和溶液结构，并提供了硫酸根磺酸盐配合物的NMR光谱的详细分配。七个络合物中的四个含有螯合配位的氧阴离子（硫酸根，甲酸根，硝酸根，碳酸根）。这些物质与相应的diaqua复合物之间的平衡通常较慢。测量了在25摄氏度下5 mol dm（-3）高氯酸中的平衡速率，硫酸盐，甲酰胺和碳酸盐物种的半衰期分别为20分钟，10分钟和3小时。硝基络合物的相应反应的半衰期少于3分钟。 Co（[2（4）.3（1）] adz）（HCO3）（2+）离子的浓度酸解离常数经测量为Ka = 0.33 mol dm（-3）[25摄氏度，I = 2 mol dm（-3）]和Ka = 0.15 mol dm（-3）[25摄氏度，I = 5 mol dm（-3）]。发现硫酸盐配位的倾向足够大，以使碳酸根络合物向硫酸根络合物的定量转化发生在含有少量硫酸盐污染的3 mol dm（-3）三氟甲磺酸中。在此基础上，对较大的大双环四胺配体[3（5）] adz的相应钴（III）碳酸根络合物在5 mol dm（-3）三氟甲磺酸中的脱羧作用进行了重新研究，发现也导致硫酸根团络合物。讨论了两个金刚烷配体的钴（III）配合物的氧阴离子配体交换速率的差异，这归因于分子结构的基本差异，其中倒置的con。对于较大的[3（5）] adz配体的配合物，可以看到仲非桥接胺基的结构。高af。这两个钴（III）-金刚烷部分的氧阴离子的螯合配位性基于N-Co-N角而合理化。比较了一系列金刚烷配合物的N-Co-N角，并讨论了结构后果。

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