Different liquid crystalline phases with long-range orientational but not positional order, so-called nematic phases, are scarce. New nematic phases are rarely discovered, and such an event inevitably generates much interest. Here, we describe a transition from a uniaxial to a novel nematic phase characterized by a periodic splay modulation of the director. In this new nematic phase, defect structures not present in the uniaxial nematic phase are observed, which indicates that the new phase has lower symmetry than the ordinary nematic phase. The phase transition is weakly first order, with a significant pretransitional behavior, which manifests as strong splay fluctuations. When approaching the phase transition, the splay nematic constant is unusually low and goes towards zero. Analogously to the transition from the uniaxial nematic to the twist-bend nematic phase, this transition is driven by instability towards splay orientational deformation, resulting in a periodically splayed structure. And, similarly, a Landau-de Gennes type of phenomenological theory can be used to describe the phase transition. The modulated splay phase is biaxial and antiferroelectric.

Pd3-type clusters generated from Pd(OAc)2/nPPh3, formed via a dinuclear Pd(i) species, exhibit high activity in Suzuki–Miyaura cross-coupling.

Emissive gold(iii) complexes with liquid-crystalline properties have been prepared, with most complexes showing a columnar hexagonal phase. The emissive response has been characterised in solution and in OLED devices.

It has been shown for the first time that the Pt complex cis-[Pt(N^C-tolpy) Cl ] (tolpy=2-(4-tolyl)pyridinyl) can be prepared in a one-pot reaction from K [PtCl ], although analogous complexes containing 2,5-bis(4-dodecyloxyphenyl)pyridine (=HL) could be prepared using existing routes. The resulting complexes cis-[Pt(N^C-L) Cl ] are liquid crystals and small-angle X-ray scattering suggests formation of a lamellar mesophase. Surprisingly, heating [Pt(κ -N^C-L) Cl(κ -N^C-LH)] also leads to a mesomorphic compound, which results from thermally induced oxidation to cis-[Pt(N^C-L) Cl ] and what is presumed to be another geometric isomer of the same formula. The Pt complexes are quite strongly luminescent in deoxygenated solution, with φ≈10 % and show vibrationally structured emission spectra, λ (0,0)=532 nm, strongly displaced to the red compared to cis-[Pt(N^C-tolpy)Cl ]. Long luminescence lifetimes of 230 μs are attributed to a lower degree of metal character in the excited state accompanying the extension of conjugation in the ligand. There is no significant difference between the emission properties of the bromo- and chloro-complexes, in contrast with the known complexes cis-[Pt(N^C-ppy)X ], where the quantum yield for X=Br is some 30 times lower than for X=Cl (ppyH=2-phenylpyridine). The lower energy of the excited state in the new complexes probably ensures that deactivating LLCT/LMCT states remain thermally inaccessible, even when X=Br.