NITROGEN-NITROGEN STRETCHING BAND IN HYDRAZINE DERIVATIVES AND COMPLEXES
NITROGEN-NITROGEN STRETCHING BAND IN HYDRAZINE DERIVATIVES AND COMPLEXES
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DOI：
10.1021/ic50065a034
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发表时间：
1968-01-01
影响因子：
4.6
通讯作者：
LEPORATI, E
中科院分区：
文献类型：
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作者：
BRAIBANTI, A;DALLAVALLE, F;LEPORATI, E
交错肼分子中氮原子的孤电子对之间的排斥力影响氮-氮键的长度；排斥力的减小导致肼衍生物中的键缩短，其中孤对电子被吸引到键上。考察了几种肼衍生物的红外光谱：y(NN)的位移与这一观点一致。当孤对电子之间的排斥力减弱时，能带从 880 cm'1 移动到 1000 cm'1。在肼的金属络合物中，即使氮-氮键距保持不变，也可以观察到能带的移动，这取决于金属阳离子对孤对电子对的场效应。肼分子H2N-NH2由两个交错构型的四面体组成，每个四面体的2个角被一个孤对电子占据。固体肼中氮-氮键距为 NN= 1.46 A3，但在阳离子+ H3NNH3+(NN= 1.40 Á4) 和阳离子 H2N-NH3+(NN= 1.432, 6 1.435 Á6) 中氮-氮键距变短。这种缩短不能归因于二甲酰基键合的增加
The repulsion between the lone electron pairs of the nitrogen atoms in the staggered hydrazine molecule influences the length of the nitrogen-nitrogen bond; diminution of the repulsion causes shortening of the bond in those derivatives of hydrazine where the lone pair is attracted to bonds. The infrared spectra of several hydrazine derivatives havebeen examined: the shifts of y (NN) are in agreement with this point of view. The band shifts from 880 toward 1000 cm'1 when the repulsion between the lone pairs diminishes. In metal complexes of hydrazine, shifts of the band are also observed, depending on the field effect of the metal cations on the lone pairs, even if the nitrogen-nitrogen bond distance remains unaltered.The hydrazine molecule H2N-NH2 is composedof two tetrahedra in staggered configuration, 2 one corner in each being occupied by a lone pair. The nitrogen-nitrogen bond distance is NN= 1.46 A3 in solid hydrazine but it becomes shorter in the cation+ H3NNH3+(NN= 1.40 Á4) and in the cation H2N-NH3+(NN= 1.432, 6 1.435 Á6). This shortening cannot be attributed to increments in bonding as for diformyl-