This paper describes a microdroplet merging device that can actively control the merging of various droplets under a wide range of flow conditions, using a simple structure. The microdroplets were trapped and merged in a wide chamber divided by pillars, and their behavior was controlled by two horizontal pneumatic microactuators. Hydrodynamic flow control by the actuation was evaluated numerically, and the trapping and merging of droplets were achieved experimentally and controlled via pressure applied to the microactuators. Furthermore, two independently generated droplets were merged under four different modes, ranging from no merging to four-droplet merging, with different ratios and volumes. The pneumatic actuators allowed not only the control of the number of merged droplets, but also a wide range of applied droplet volumes. The device was fabricated simply using a single-layer PDMS (polydimethylsiloxane) structure, and the continuous merging performance operated using only hydrodynamic flow control without any surfactant. Finally, chemical synthesis of a metal complex was performed by the droplet merging method. Crystallization of the complex was visualized in real time, and the synthesis was verified by ultraviolet-visible spectroscopy.

Naphtheledicarboxylato ((NDC 2− ) bridged coordination polymers (CPs) along with (E)-1-methyl-2-(p-chlorophenylazo)imidazole (ClPai-Me) coordination to Co(II), [Co(∝-NDC) 0.5 (∝ 4 -NDC) 0.5 (ClPai-Me)]•0.5H 2 O (1), and to Zn(II), [Zn(∝-NDC) 0.5 (∝ 4 -NDC) 0.5 (ClPai-Me)]•0.5H 2 O (2), have been characterized. In the single crystal X-ray structure of 1, ClPai-Me chelates to the Co(II) ion by N(azo) and N(imidazolyl), whereas in compound 2, it acts as a monodentate N(imidazolyl) donor to the Zn(II) ion. The coordination atmosphere around Co(II) in the 1 ion is distorted octahedral CoN 2 O 4 , whereas in the case of 2, it is distorted square pyramidal ZnNO 4 . Compounds 1 and 2 exhibit the righthanded (P) and left-handed (M) one-dimensional helical chain. NDC −2 is serving as a bridge between two M(II) ions to constitute μ-NDC and four M(II) ions to construct μ 4 -NDC to assemble threedimensional polymers. Upon UV light (369 nm) irradiation, compound 2 shows trans-to-cis isomerization of -NN−C 6 H 4 −Clp both in the solid and solution state but 1 remains silent. Prolonged light irradiation in the solid state (film phase) does not change the coordinated ClPai-Me in complexes 1 and 2, whereas the free stage of ClPai-Me undergoes photoreduction of the −NN− bond and forms azo radicals with a concomitant permanent color change. The persistence of the radical has been characterized by electron paramagnetic resonance spectroscopy in the solid state at g = 2.009. The effective magnetic moment of 1 is 4.17 μ B at 300 K, Co(II) ion of S = 3/2.

Key indicatorsSingle-crystal X-ray study T = 297 K Mean (C-C) = 0.011 Å R factor = 0.046 wR factor = 0.128 Data-to-parameter ratio = 10.6For details of how these key indicators were automatically derived from the article, see

We have synthesized carboxylato-bridged paddle-wheel Cu(II) coordination polymers [Cu 2 (DABA) 4 -(4,4′-BPY)] n (1) and [Cu 4 (DABA) 8 (PYZ)(H 2 O) 2 ] (2) by varying the axial linkers 4,4′-bipyridine (4,4′-BPY) and pyrazine (PYZ) (HDABA = 4-diallylamino-benzoic acid).The single-crystal X-ray structure of 1 is a one-dimensional polymer, while 2 is a zero-dimensional tetranuclear Cu(II) complex. Upon light irradiation, the thin film of the compounds increases the electrical conductivity with respect to the dark phase, and the conductivity of 1 is ∼150 times higher than 2. Magnetic properties were investigated at an applied field 0.5 T in a temperature range 5−300 K. Compound 1 exhibited ferromagnetic behavior, compound 2 exhibited antiferromagnetic behavior at 300 K, and the effective magnetic moment at 300 K is 1.94 and 0.93 B.M. respectively. The capability to switch photoelectricity and magnetism by changing the crystal structure via the axial linker's modification has been rationalized through density functional theory calculations.

a b s t r a c tA series of palladium(II) complexes involving CeH and NeH bond activations of the R 1 rings of thiosemicarbazones {R 1 (R 2 )C 2 eN 3 eN 2 (H)eC 1 (]S)eN 1 HR 3 ; R 1 , R 2 : thiopheneyl, Me, H 2 L 1 (R 3 ¼ Me), H 2 L 2 (R 3 ¼ Ph); R 1 , R 2 : Ph, Me, H 2 L 3 (R 3 ¼ Me), H 2 L 4 (R 3 ¼ Ph); R 1 , R 2 : Ph, Ph, H 2 L 5 (R 3 ¼ Me), H 2 L 6 (R 3 ¼ Ph) and R 1 , R 2 : pyrrole, Me, H 2 L 7 (R 3 ¼ Me), H 2 L 8 (R 3 ¼ Ph)} are described. Methyl group (R 2 ) at C 2 carbon in H 2 L 1 and H 2 L 2 induced CeH bond activation of the thiopheneyl ring and formed cyclometallated complexes, [Pd(k 3 eC 4 ,N 3 ,SeL)(PPh 3 )] (L ¼ L 1 , 1; L 2 , 2). Similarly, phenyl rings (R 1 ) in H 2 L 3 , H 2 L 4 , H 2 L 5 , H 2 L 6 at C 2 carbon have shown CeH activations forming cyclometallated complexes, [Pd(k 3 eC 4 ,N 3 ,SeL)(PPh 3 )] (L ¼ L 3 , 3; L 4 , 4; L 5 , 5; L 6 , 6). However, pyrrole ring did not exhibit similar CeH activation behavior, rather involved NeH activation and formed complexes, [Pd(k 3 eN 4 ,N 3 ,SeL)(PPh 3 )] {L ¼ L 7 , 7; L 8 , 8}. All these complexes have been characterized with the help of analytical data, spectroscopic techniques (IR, 1 H and 31 P NMR), and single crystal X-ray crystallography (1, 2, 4, 5, 7 and 8). The thiosemicarbazone ligands behave as dinegative C 4 , N 3 , S-chelating in 1e6 and N 4 , N 3 , S-chelating in complexes 7 and 8. Interestingly, complexes 2, 4 and 8, with phenyl substituent at N 1 atom, have two independent molecules in their respective crystal lattices.