Department of Chemistry, University of Stellenbosch, Private Bag X1, Matieland, Stellenbosch, South Africa.
Dalton Trans. 2013 Oct 7;42(37):13349-56. doi: 10.1039/c3dt32872d. Epub 2013 Jun 3.
DFT calculations using BP86 in conjunction with the SVP and TZVPP basis sets as well as ab initio calculations at SCS-MP2 have been carried out for six dicoordinated carbon molecules CLL' where L is a fluorenyl carbene while L' is a phosphine PH3 (1) or PPh3 (2) or a carbene, i.e. NHCMe (3), benzannulated NHCMe (4), cycloheptatrienylidene (5) and benzannulated cycloheptatrienylidene (6). The complexes of these compounds with one and two AuCl moieties were also calculated. The monoaurated adducts of 1-4 have the AuCl fragment η(1) coordinated to the central carbon atom. The complexes 5(AuCl) and 6(AuCl) have AuCl η(2) bonded across a C=C double bond. Three different bonding modes are found as energy minima for the diaurated species LL'C-(AuCl)2. The AuCl fragments are found to be either both coordinated η(1), both coordinated η(2) across double bonds, or a combination of the two. According to the electronic structure analysis of the free compounds, 1 and 2 might best be classified as carbenes, 3 and 4 as bent allenes while 5 and 6 are typical allenes. The complexation with AuCl reveals that 1-4 may exhibit chemical behaviour which is typical for carbones and thus, they may be termed "hidden carbones". The AuCl complexes show that compounds 5 and 6 are classical allenes.
使用 BP86 与 SVP 和 TZVPP 基组以及 SCS-MP2 从头算相结合，对六个六配位碳分子 CLL'进行了 DFT 计算，其中 L 是芴基卡宾，而 L'是膦 PH3（1）或 PPh3（2）或卡宾，即 NHCMe（3）、苯并环庚二烯基 NHCMe（4）、环庚三烯基（5）和苯并环庚三烯基（6）。这些化合物与一个和两个 AuCl 部分的配合物也被计算出来。1-4 的单金化加合物具有 η(1)配位到中心碳原子的 AuCl 片段。配合物 5(AuCl)和 6(AuCl)具有 η(2)键合在 C=C 双键上的 AuCl。对于二金化物种 LL'C-(AuCl)2，发现了三种不同的成键模式作为能量极小值。AuCl 片段被发现要么都是 η(1)配位，要么都是 η(2)跨越双键配位，或者两者的组合。根据游离化合物的电子结构分析，1 和 2 最好被归类为卡宾，3 和 4 是弯曲的丙二烯，而 5 和 6 是典型的丙二烯。与 AuCl 的络合表明，1-4 可能表现出典型的卡宾的化学行为，因此，它们可以被称为“隐藏的卡宾”。AuCl 配合物表明化合物 5 和 6 是典型的丙二烯。
