Synthesis using metal vapors. Silver carbonyls. Matrix infrared, ultraviolet-visible, and electron spin resonance spectra, structures, and bonding of silver tricarbonyl, silver dicarbonyl, silver monocarbonyl, and disilver hexacarbonyl
Synthesis using metal vapors. Silver carbonyls. Matrix infrared, ultraviolet-visible, and electron spin resonance spectra, structures, and bonding of silver tricarbonyl, silver dicarbonyl, silver monocarbonyl, and disilver hexacarbonyl
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使用金属蒸气合成。
DOI：
10.1021/ja00427a018
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发表时间：
1976
影响因子：
15
通讯作者：
G. Ozin
中科院分区：
文献类型：
--
作者：
D. Mcintosh;G. Ozin
由银蒸气和一氧化碳在6 - 15 K温度范围内的共缩合反应合成了迄今未知的顺磁性绿色配合物Ag（CO）j。三羰基络合物和单核制剂载体的表征来自几个来源：（a）混合，2C 160/13C 160和12C 160/12C 180同位素取代，频率和强度计算，（B）银浓度实验，（c）Cu和Ag蒸气与CO的同时蒸发和共冷凝，（d）紫外-可见光谱，和（e）ESR光谱。当Ag（CO）3在纯CO中合成时，振动数据与略微扭曲的三角形平面结构一致，朝向Civ或C2，可能反映了该分子在固体CO中的低取代位点的稳定性。然而，当在Ar，Kr或Ar基质中合成时，Ag（CO）3似乎采用规则的Du结构。Ag（CO）_3在CO-Ar基质中的ESR谱支持Ag（CO）_3具有轴对称性（g|| = 2.012和g ± = 1.995）。相应的紫外-可见光谱与具有2 π "电子基态的三角平面分子的预期光谱一致，这与Ag（CO）3与Cu（CO）3相比的所有光学跃迁的蓝移是一致的。与相应的铜蒸气-一氧化碳反应不同，在高浓度银下，Ag与CO的基体反应不能合成Ag（CO）_6。然而，Ag（CO）_3在纯CO中具有热不稳定性和光化学不稳定性，在20 - 35 K的升温实验中，Ag（CO）_3发生了一个简单的二聚反应，生成Ag_2（CO）_6。另一方面，对Ag（CO）3在Kr和KBr基质中进行的预热实验表明，该分子在至少80 - 100 K下是稳定的。在这些条件下，Ag（CO）3没有分解或二聚化的倾向。Ag（CO）3的热行为表明，在纯CO中存在某种基质辅助扩散过程。根据最近Ag（CO）3在纯CO中二聚反应的基质动力学研究，讨论了可能的扩散机制。使用与Ag（CO）3相似的方法，本文报道了在Ar、Kr和H2O中Ag（CO）2和Ag（CO）配合物的合成和表征。从完整系列的配合物M（CO）n（其中M = Cu或Ag;= 1 - 3）的红外和紫外-可见光谱中提取的信息用于得出关于它们的分子和电子结构、热力学稳定性和成键性质的结论。特别感兴趣的是观察到的Cotton-Kraihanzel CO键拉伸力常数的异常行为。提出了一种合理化的解释，即Nd~（10）价壳层非常稳定，能量可及的价P~n金属轨道参与了整个成键方案。在本文中，对最近合成的Al，Ga，Ge和Sn的主族羰基配合物中pT金属轨道的作用进行了评估，并对M（CO）n（M = Cu或Ag，= 1 - 3）与CO在Cu和Ag金属膜上化学吸附的数据之间的有趣关系进行了评估。最后，研究了Ag（CO）n在Ar，Kr，白金汉的非特异性溶质理论将这两个问题合理化，自1866年的失败的早期报道以来，银的羰基化学的知识状态基本上保持不变。1到目前为止，还没有报道银的稳定的羰基或羰基衍生物，并且直到最近才报道了唯一的羰基衍生物。关于Ag-CO键的现有信息是...
The heretofore unknown paramagnetic, green complex Ag (CO) j is synthesized from the cocondensation reaction of silver vapor and carbon monoxide in the temperature range 6-15 K. Characterizationof the tricarbonyl complexand support for the mononuclear formulation originate from several sources:(a) mixed, 2C160/13C160 and 12C160/l2C180 isotopic sub-stitution, frequencyand intensity calculations,(b) silver concentration experiments,(c) simultaneous vaporization and cocon-densation of Cu and Ag vapors with CO,(d) uv-visible spectroscopy, and (e) ESR spectroscopy. When Ag (CO) 3 is synthesized in pure CO, the vibrational data are consistent with a slightly distorted triangular planar structure, towards either Civ or C2, probably reflecting the low substitutional site symmetryfor the molecule in solid CO. However, when synthesized in Ar, Kr, or Xe matrices, Ag (CO) 3 appears to adopt a regular, Du,, structure. The ESR spectrum for Ag (CO) 3 in CO-Ar matrices sup-ports the contention that the molecule has axial symmetry (g||= 2.012 and g±= 1.995). The corresponding uv-visible spectrum is consistent with that expected for a trigonal planar molecule having a 2\i''electronic ground state which is compatible with the observed blue shifts for allof the optical transitionsof Ag (CO) 3 comparedto Cu (CO) 3. Unlike the correspondingcopper vapor-carbon monoxide reaction, Ag2< CO) 6 couldnot be synthesized from the matrix reaction of Agand CO at high con-centrations of silver. However, Ag (CO) 3 is found to be thermally and photochemicallylabile in pure CO. During warm-up ex-periments in the range 20-35 K, Ag (CO) 3 undergoes a facile dimerization reaction to form Ag2 (CO) 6. On the other hand, warm-up experiments performed on Ag (CO) 3 in Kr and Xe matrices demonstrate that the molecule is stable up to at least 80-100 K. Under these conditions, Ag (CO) 3 shows no tendency to decompose or dimerize. The thermal behavior of Ag (CO) 3 is taken to indicate that some kind of matrix-assisted diffusion process is operating in pure CO. Possible diffusion mechanisms are discussed in the light of recent matrix kinetic studies of the dimerization reaction of Ag (CO) 3 in pure CO. Using methods similar to those outlined for Ag (CO) 3, the synthesis and characterization of the Ag (CO) 2 and Ag (CO) complexesin Ar, Kr, and Xe are described. The information extracted from the infrared and uv-visible spectra of the complete series of complexes M (CO)„(where M= Cu or Ag;= 1-3) is used to draw conclusions about their molecular and electronic structures, thermodynamic stabilities, and bonding properties. Of special interest is the anomalous behavior observed for the Cotton-Kraihanzel CO bond stretching force constants. A rationalization interms of a very stable nd10 valence shell and the participation of ener-getically accessible valence p „metal orbitals in the overall bonding scheme are presented. In this context, the role of pT metal orbitals in the recently synthesized main group carbonyl complexes of Al, Ga, Ge, and Sn is assessed as is the interesting rela-tionship between the M (CO)„data (where M= Cu or Ag,= 1-3) and those for CO chemisorbed onto Cu and Ag metallic films. Finally, the matrix-induced frequency shifts for Ag (CO)„in Ar, Kr, and Xe are rationalized in terms of Buckingham’s theory of nonspecific solute-solvent interactions.The state of knowledge of the carbonyl chemistry of silver has remained essentially unchanged since the early reports of failure in 1866.1 Up to the present time no stable carbonyl nor carbonyl derivative of silver has been reported and until very recently the only available information pertaining to Ag-CO bonds was …