The complexes [AuI(PPh
3
)] 1,
[Au
2
(µ-dppm)Cl
2
] 2
[dppm = bis(diphenylphosphine)methane],
[Au
2
(µ-dppm)I
2
] 3,
[Au
3
(µ-tppm)Cl
3
] 4
[tppm = tris(diphenylphosphino)methane],
[Au
3
(µ-tppm)I
3
] 5,
[Au
3
(µ-dpmp)
2
Cl
2
]Cl 6
[dpmp = bis(diphenylphosphinomethyl)phenylphosphine] and
[Au
3
(µ-dpmp)
2
I
2
]I 7 were
prepared. The crystal structures of 5–7 have been
established by X-ray crystal analysis. The measured intramolecular
Au–Au distances are 3.136(1) Å in 5, 2.946(3) and
2.963(3) Å in 6 and 2.952(1) and 3.020(1) Å in
7. Extended-Hückel molecular orbital calculations revealed
that the 6p orbitals of iodide and 5d orbitals of gold(I) make a
significant contribution to the highest occupied molecular orbitals of
5 and of 2 and 4 respectively. The lowest
unoccupied molecular orbitals of these complexes mainly comprise π*
orbitals of the phosphines. The photophysical properties of
1–6 have been studied. All show dual emissions. The
low-energy emissions at around 660–680 nm have a small red shift in
energy from chloro to iodo complexes, and a much higher intensity at room
temperature than at 77 K. These are attributed to triplet states with mixed
3
m.m.l.c.t. (metal–metal to ligand charge transfer,
gold→phosphine) and
3
l.l.c.t. (ligand to ligand charge
transfer, halide to phosphine) characters. The high-energy emissions at
around 460–530 nm are more prominent at 77 K and assigned to
intraligand and or
3
m.l.c.t. (metal to ligand charge transfer)
transitions. The temperature effects on the luminescence lifetimes of these
complexes have also been studied.
复合物 [AuI(PPh 3 )] 1、[Au 2 (µ-dppm)Cl 2 ] 2 [dppm = 双(
二苯基膦)
甲烷]、[Au 2 (µ-dppm)I 2 ] 3、[Au 3 (µ-tppm)Cl 3 ] 4 [tppm = 三(
二苯基膦)
甲烷]、
[Cl 6 [dpmp = 双(
二苯基膦甲基)
苯基膦] 和 [Au 3 (µ-dpmp) 2 I 2 ]I 7。通过 X 射线晶体分析确定了 5-7 的晶体结构。测得的分子内 Au-Au 距离分别为:5 为 3.136(1) Å,6 为 2.946(3) Å 和 2.963(3) Å,7 为 2.952(1) Å 和 3.020(1) Å。扩展胡克尔分子轨道计算显示,
碘化物的 6p 轨道和
金(I)的 5d 轨道分别对 5、2 和 4 的最高占位分子轨道做出了重要贡献。这些复合物的最低未占据分子轨道主要包括膦的 π* 轨道。对 1-6 的光物理特性进行了研究。它们都显示出双重发射。波长约为 660-680 nm 的低能发射从
氯络合物到
碘络合物在能量上有微小的红移,室温下的强度比 77 K 时要高得多。这些发射归因于具有 3 m.m.l.c.t.(
金属-
金属到
配体的电荷转移,
金→膦)和 3 l.l.c.t.(
配体到
配体的电荷转移,卤化物到膦)混合特征的三重态。在 77 K 时,波长约为 460-530 nm 的高能发射更为突出,这归因于
配体内跃迁和或 3 m.l.c.t.(
金属到
配体的电荷转移)跃迁。此外,还研究了温度对这些复合物发光寿命的影响。