Solvent-Dependent Assemblies of Trinuclear Copper Cluster into Variable Frameworks Based on Mixed Ligands of Polyalcohol Amines and Organic Carboxylates

A systematic investigation on solvent-dependent assembly of trinuclear copper cluhster has resulted in eight related coordination polymers: Cu₃(teaH₂)₂(oba)₂(MeOH)₂ (<b>1</b>), Cu₃(teaH₂)₂(oba)₂(EtOH)₂ (<b>2</b>), Cu₃(teaH₂)₂(oba)₂·(<i>n</i>-PrOH) (<b>3</b>), Cu₃(teaH₂)₂(oba)₂ (<b>4</b>), Cu₃(teaH₂)₂(oba)₂(H₂O)₂ (<b>5</b>), Cu₃(MedeaH)₂(oba)₂(MeOH)₂ (<b>6</b>), Cu­[Cu₃(Medea)₂(oba)₂]·(solvent)_<i>x</i> (<b>7</b>), and [Cu₃(MedeaH)₂(oba)₂(H₂O)]·(<i>n</i>-PrOH)₂ (<b>8</b>) where oba = 4,4′-oxy-bis­(benzoate), teaH₃ = triethanolamine, and MedeaH₂ = <i>N</i>-methyldiethanolamine. In <b>1</b>–<b>8</b>, the trinuclear copper secondary building units (SBUs) (Cu₃) are furnished via the synergistic coordination of two organic ligands with metal centers. The structures of <b>1</b>–<b>8</b> exhibit two types of extensible modes (mode <b>I</b> for <b>1</b>, <b>2</b>, <b>3</b>, <b>7</b>, <b>8</b> and mode <b>II</b> for <b>4</b>, <b>5</b>, <b>6</b>) to Cu₃ SBUs. Mode <b>I</b> assembles Cu₃ SBUs into the one-dimensional (1D) iron-chain-like structure while mode <b>II</b> facilitates the two-dimensional (2D) undulate rectangular (4, 4) connection. Compounds <b>1</b> and <b>2</b> feature zero-dimensional (0D) molecular structures in which two strong hydrogen-bonding interactions extend its molecular components into 1D chains. Compound <b>3</b> comprises 1D chains interspersed by free solvent molecules, whereas compound <b>4</b> consists of 2D sheets excluding any solvent molecules. Compound <b>5</b> is also made up of 0D molecular structures but uses two classic hydrogen-bonding interactions to form its 2D supramolecular connection. Compound <b>6</b> has a 2D network similar to <b>4</b>. Compound <b>7</b> shows an unusual three-dimensional (3D) microporous framework in which a 1D chain is further assembled by extra Cu^II ions. Compound <b>8</b> provides 1D solvated structures with the voids occupied by lattice solvent molecules. The coordination ability of solvent molecules has been established for the underlying factor behind the different assemblies of compounds <b>1</b>–<b>8</b>. Compounds <b>5</b> and <b>8</b> from an alcohol/H₂O mixture indicate a behavior of selective coordination to the available coordination points of metal centers. The gas sorption property of compound <b>7</b> has also been investigated

Characteristics of Y3Fe5O12 ceramic at mid-infrared wavelengths and its Faraday isolator application

In this study, the Faraday effects of Y3Fe5O12 (YIG) magneto-optic (MO) ceramics synthesized by hot-press sintering were tested and compared with commercial YIG single crystals and Bi-doped iron garnet (BIG) films at mid-infrared wavelengths. Among them, YIG ceramics have shown Faraday rotation angles as large as 114 deg/cm and 60 deg/cm at 2.1 µm and 3.8 µm, respectively. The corresponding YIG ceramic-based Faraday isolators (FIs) exhibited an extinction ratio of 25.26 dB and an insertion loss of 1.01 dB at 2.1 µm, and an extinction ratio of 28.30 dB and an insertion loss of 1.17 dB at 3.8 µm. Under high repetition rate pulsed laser radiation, surface damage was observed for both YIG ceramic and YIG crystal at similar laser power density. Combining its advantage of size scalability, the further improvement of YIG ceramic optical quality is expected to provide a superior approach for realizing high power mid- infrared FIs