Active Property-Structure Integrated Reconfiguration of Individual Resonant Nanoparticles.

Property-structure reconfigurable nanoparticles (NPs) provide additional flexibility for effectively and flexibly manipulating light at the nanoscale. This has facilitated the development of various multifunctional and high-performance nanophotonic devices. Resonant NPs based on dielectric active materials, especially phase change materials, are particularly promising for achieving reconfigurability. However, the on-demand control of the properties, especially the morphology, in individual dielectric resonant NP remains a significant challenge. In this study, we present an all-optical approach for one-step fabrication of Ge2Sb2Te5 (GST) hemispherical NPs, integrated active reversible phase-state switching, and morphology reshaping. Reversible optical switching is demonstrated, attributed to reversible phase-state changes, along with unidirectional modifications to their scattering intensity resulting from morphology reshaping. This novel technology allows the precise adjustment of each structural pixel without affecting the overall functionality of the switchable nanophotonic device. It is highly suitable for applications in single-pixel-addressable active optical devices, structural color displays, and information storage, among others.

N-(4-Isopropoxyphen-yl)acetamide.

In the mol-ecule of the title compound, C(11)H(15)NO(2), the planar acetamide unit [maximum deviation of 0.0014 (6) Å] is oriented at a dihedral angle of 19.68 (4)° with respect to the aromatic ring. An intra-molecular C-H⋯O inter-action results in the formation of a six-membered ring. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into chains along the a axis.

Methyl 2-amino-4-(3-chloro-prop-oxy)-5-methoxy-benzoate.

The asymmetric unit of the title compound, C(12)H(16)ClNO(4), contains two crystallographically independent mol-ecules. The benzene rings of the two independent mol-ecules are oriented at a dihedral angle of 88.50 (3)°. Intra-molecular N-H⋯O hydrogen bonds involving the methoxybenzoate carbonyl group in each molecule result in the formation of two planar, six-membered rings, oriented at dihedral angles of 1.39 (3) and 0.68 (3)° with respect to the adjacent benzene rings. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into chains along the a axis.

5-Chloro-pyrimidin-2-amine.

The complete mol-ecule of the title compound, C(4)H(3)ClN(3), is generated by crystallographic mirror symmetry, with the Cl atom, one N atom and two C atoms lying on the reflecting plane. In the crystal structure, inter-molecular N-H⋯N hydrogen bonds link the mol-ecules into chains propagating in [100].

2-[2-(4-Nitro-phenyl)hy-dra-zin-yl-idene]malononitrile.

The title compound, C(10)H(8)N(8), is close to planar (r.m.s. deviation from the mean plane = 0.118 Å). In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds generate R(2) (2)(12) loops.

Methyl 4-(3-chloro-prop-oxy)-3-methoxy-benzoate.

In the title compound, C(12)H(15)ClO(4), the molecules are linked by C-H⋯O interactions.

4-[4-(4-Nitro-phenyl-diazen-yl)phen-yl]hexa-nenitrile.

In the mol-ecule of the title compound, C(18)H(18)N(4)O(2), the aromatic rings are oriented at a dihedral angle of 3.72 (3)°. In the crystal structure, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into centrosymmetric dimers. There are also C-H⋯π inter-actions.

Methyl 4-but-oxy-3-methoxy-benzoate.

The title compound, C(13)H(18)O(4), is an inter-mediate product in the synthesis of quinazoline derivatives. Crystal structure analysis shows that the benzene-butoxy C(ar)-O-C-C torsion angle is 175.3 (2)° and that the benzene-methoxycarbonyl C(ar)-C-O-C torsion angle is 175.2 (2)°. Torsion angles close to 180° indicate that the molecule is almost planar.

Bis{6-[4-(2-ethyoxyphenyl-diazen-yl)phen-oxy]hexa-nol} monohydrate.

The asymmetric unit of the title compound, 2C(20)H(26)N(2)O(3)·H(2)O, contains two independent mol-ecules and one water mol-ecule. The azo bonds adopt trans conformations and the dihedral angles between the aromatic rings in the two organic mol-ecules are 4.5 (2) and 1.5 (2)°. In the crystal structure, O-H⋯O and C-H⋯O hydrogen bonds help to establish the packing.

Methyl 5-meth-oxy-2-nitro-4-[3-(piperidin-1-yl)prop-oxy]benzoate.

In the mol-ecule of the title compound, C(17)H(24)N(2)O(6), the dihedral angle between the four coplanar atoms of the piperidine ring and the benzene ring is 39.2 (1)°.

2-{3,4-Dibut-oxy-5-[5-(3-methyl-phen-yl)-1,3,4-oxadiazol-2-yl]thio-phen-2-yl}-5-(3-methyl-phen-yl)-1,3,4-oxadiazole.

In the title compound, C(30)H(32)N(4)O(4)S, the dihedral angles between the central thio-phene ring and the pendant oxadiazole rings are 10.1 (2) and 6.8 (3)°. The dihedral angles between each oxadiazole ring and its adjacent benzene ring are 6.8 (2) and 5.3 (3)°.

Methyl 4-(3-chloro-prop-oxy)-5-meth-oxy-2-nitro-benzoate.

The asymmetric unit of the title compound, C(12)H(14)ClNO(6), contains two crystallographically independent mol-ecules, in which the benzene rings are oriented at a dihedral angle of 9.12 (3)°. In the crystal structure, weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional network.

2-(4-tert-Butyl-phen-yl)-5-{3,4-dibutoxy-5-[5-(4-tert-butyl-phen-yl)-1,3,4-oxadiazol-2-yl]-2-thienyl}-1,3,4-oxadiazole.

In the title compound, C(36)H(44)N(4)O(4)S, the dihedral angles between the central thio-phene ring and the pendent oxadiazole rings are 12.7 (2) and 13.7 (2)°, and the dihedral angles between the oxadiazole rings and their adjacent benzene rings are 6.1 (2) and 17.5 (2)°. An intra-molecular C-H⋯O inter-action may help to establish the conformation.

5,5'-Diethyl-2,2'-(triazene-1,3-di-yl)di-1,3,4-thia-diazole.

In the mol-ecule of the title compound, C(8)H(11)N(7)S(2), the conformation about the N=N bond is trans and the thia-diazole rings are oriented at a dihedral angle of 2.92 (3)°. In the crystal structure, inter-molecular N-H⋯S hydrogen bonds link the mol-ecules into chains. There are π-π contacts between the thia-diazole rings [centroid-to-centroid distances = 3.699 (3) and 3.720 (2) Å].

2-Methyl-3-nitro-benzonitrile.

The asymmetric unit of the title compound, C(8)H(6)N(2)O(2), contains two independent mol-ecules, the aromatic rings of which are oriented at a dihedral angle of 1.68 (3)°. Intra-molecular C-H⋯O hydrogen bonds result in the formation of two non-planar six-membered rings, which adopt envelope and twisted conformations. In the crystal structure, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules. There are π-π contacts between the benzene rings [centroid-centroid distances = 3.752 (3) and 3.874 (3) Å].