已经制备了具有叔丁基表面基团的新型的基于扭曲的刚性联苯基树突,并将其附着在绿色的发射性fac -tris(2-苯基吡啶基)铱(III)核上。分别制备了一个(每个配体一个树枝状分子)和一个双重(每个配体两个树枝状分子)树枝状化的第一代树枝状大分子。在这两种情况下,溶液的光致发光量子产率(PLQY)均比由非刚性联苯-树枝状分子和相同核组成的等效树枝状聚合物高出10%以上,而双树枝状化合物具有几乎定量的PLQY。然而,对于这两种材料有在固态的PLQY指示显著减少,虽然吨丁基可以提供一定程度的溶解性,它们不会屏蔽发射核以及具有更长长度的表面基团(例如2-乙基己氧基)。当双树突状材料与4,4',4''-三(咔唑-9-基)三苯胺混合时,薄膜PLQY接近溶液测量的水平,并且简单的两层器件由发射层和电子传输组成1,3,5-三(3-吡啶基-3-苯基)苯的/空穴阻挡层达到了约10000 cd m -2的最大亮度和16
A charge-neutral organometallic dendrimer is described, said dendrimer having the formula (I):
CORE-[DENDRITE(-Q)
a
]
n
(I)
in which CORE represents a group of formula MX
x
Y
z
, in which M represents a metal cation, x represents an integer of 1 or more, each X which may be the same or different represents a mono-, bi- or tri-dentate coordinating group, z represents 0 or an integer of 1 or more, and each Y which may be the same or different represents a coordinating group, the total of (b.x)+(c.z) being equal to the number of coordination sites on M, wherein b is the number of coordination sites on X and c is the number of coordination sites on Y; n represents an integer of 2 or more; each DENDRITE which may be the same or different represents a dendritic molecular structure bonded to a group X; a represents 0 or an integer of 1 or more; and each Q which may be the same or different represents a surface group; CORE terminating in the first single bond which is connected to a branching group or branching atom of DENDRITE; which dendrimer has a structure in which no hemisphere of a notional sphere centred on M and containing the dendrimer is devoid of a said first single bond.
A charge-neutral organometallic dendrimer is described, said dendrimer having the formula (I):
CORE-[DENDRITE(-Q)
a
]
n
(I)
in which CORE represents a group of formula MX
X
Y
Z
, in which M represents a metal cation, x represents an integer of 1 or more, each X which may be the same or different represents a mono-, bi- or tri-dentate coordinating group, z represents 0 or an integer of 1 or more, and each Y which may be the same or different represents a coordinating group, the total of (b.x)+(c.z) being equal to the number of coordination sites on M, wherein b is the number of coordination sites on X and c is the number of coordination sites on Y; n represents an integer of 2 or more; each DENDRITE which may be the same or different represents a dendritic molecular structure bonded to a group X; a represents 0 or an integer of 1 or more; and each Q which may be the same or different represents a surface group; CORE terminating in the first single bond which is connected to a branching group or branching atom of DENDRITE; which dendrimer has a structure in which no hemisphere of a notional sphere centred on M and containing the dendrimer is devoid of a said first single bond.