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Abstract Osmoregulation and osmoconformation are two mechanisms through which aquatic animals adapt to salinity fluctuations. The euryhaline crab Scylla paramamosain, being both an osmoconformer and osmoregulator, is an excellent model organism to investigate salinity adaptation mechanisms in brachyurans. In the present study, we used transcriptomic and proteomic approaches to investigate the response of S. paramamosain to salinity stress. Crabs were transferred from a salinity of 25 ppt to salinities of 5 ppt or 33 ppt for 6 h and 10 days. Data from both approaches revealed that exposure to 5 ppt resulted in upregulation of ion transport and energy metabolism associated genes. Notably, acclimation to low salinity was associated with early changes in gene expression for signal transduction and stress response. In contrast, exposure to 33 ppt resulted in upregulation of genes related to amino acid metabolism, and amino acid transport genes were upregulated only at the early stage of acclimation to this salinity. Our study reveals contrasting mechanisms underlying osmoregulation and osmoconformation within the salinity range of 5–33 ppt in the mud crab, and provides novel candidate genes for osmotic signal transduction, thereby providing insights on understanding the salinity adaptation mechanisms of brachyuran crabs.

Abstract  A new ion-pair complex, bis(1-benzyltriphenylphosphinium) bis(1,2,5-thiadiazole-3,4-dithiolato)nickelate(II), [BzTPP]2[Ni(tdas)2](1), has been prepared and characterized by elemental analyses, UV, IR, MS spectrum, molar conductivity and single crystal X-ray diffraction. The title complex crystallizes in the triclinic space group P-1, a = 9.098(1) Å, b = 9.666(1) Å, c = 29.573(3) Å, α = 83.81(1)°, β = 81.97(1)°, γ = 78.83(1)°, V = 2,517.5(4) Å3, Z = 2. The unit cell contains two [BzTPP]+ and two halves of [Ni(tdas)2]2− anions in which the anion exhibits a quasi-planar structure. The [BzTPP]+ cation adopts a conformation where four phenyl rings are twisted to the C–C–P reference plane. The weak cation–cation C–H···π, π···π interactions and anion–cation C–H···N hydrogen bonds between the anion and cation play an important role in the stacking and stabilizing of the title complex. Graphical Abstract  The title new ion-pair complex, bis(1-benzyltriphenylphosphinium) bis(1,2,5-thiadiazole-3,4-dithiolato)nickelate(II), [BzTPP]2[Ni(tdas)2](1), contains two [BzTPP]+ and two halves of [Ni(tdas)2]2− anions in which the weak cation–cation C–H···π, π···π interactions and anion−cation C–H···N hydrogen bonds between the anion and cation play an important role in the stacking and stabilizing of the title complex. [ABSTRACT FROM AUTHOR]

Four new one-dimensional (1D) polymeric complexes, {[Cu4(L1)2(µ-Br)2(µ4-CO3)]Br(ClO4)3·3H2O}n(1), {[Cu2L2(µ-Cl)Cl2] (ClO4)2·H2O}n(2), {[Cu2L3(µ-Cl)2](ClO4)2}n(3), and {[Cu2L4(µ-Cl)2](ClO4)2}n(4), have been synthesized and characterized, where L1= N,N,N′,N′-tetrakis(3′-aminopropyl)-1,3-propylenediamine, L2= N,N,N′,N′-tetrakis(2′-aminoethyl)-1,3-propylenediamine, L3= N,N,N′,N′-tetrakis(2′-aminoethyl)-1,4-butylenediamine, L4= N,N,N′,N′-tetrakis(2′-aminoethyl)-1, 6-hexylenediamine. X-Ray structure analysis revealed that the polymeric complexes, created by the bridging groups which are exhibited in the formula, present different 1D coordination motifs: double-stranded chains with voids of 43.5 Å2for 1, sigmoid chains for 2, zigzag chains for 3and 4with different coordination polyhedra. Various hydrogen bonding interactions such as N–HCl, N–HO, C–HCl, N–HBr and O–HBr join the polymeric chains to generate two-dimensional networks with bigger voids. Magnetic susceptibility data were fitted according to the molecular structures using Hamiltonians: H= −2J1(S2S3+ S1S4) − 2J2(S2S1) − 2J3(S1S3+ S2S4) − 2J4(S3S4), which corresponds to a rectangular array of spins for 1, and H= −2JS1S2corresponds to a dinuclear array of spins for 2, 3and 4. It was found that the coupling constants of 1are −60, −113, −54 and −11 cm−1, and those of 2, 3, and 4are −2.46, −1.56 and −0.15 cm−1, respectively. [ABSTRACT FROM AUTHOR]

A new fluorenyl-substituted dioxotetraamine salicylaldehyde Schiff-base ligand (L1) has been synthesized by the non-template 1 + 2 condensation of ligand 6-(9-fluorenyl)-1,4,8,11-tetraazaundecane-5,7-dione (L) with salicylaldehyde. From reduction of L1 with an excess of NaBH4, a ditopic dioxotetraamine ligand (L2) has been obtained. The copper(ii) complex of L1 has been synthesized and its properties were examined by ES-MS and variable-temperature magnetic susceptibility as well as its crystal structure being determined. Detailed studies have been made on solution chemistry of Cu(ii) complex of L2 by pH-potentiometric and fluorometric titration. [ABSTRACT FROM AUTHOR]

Two unsymmetrical, macrocyclic, heterodinuclear complexes, [Cu II M II (L)] (ClO 4 ) 2 · n H 2 O ( n = 3; M = Zn, Cd) have been obtained by cyclocondensation of N , N ′- bis (3-formyl-5- n -butylsalicylidene)ethylenediimine and 1,3-diaminopropane in the presence of M 2+ . The structures of both complexes were determined by X-ray diffraction techniques. In each complex, two metals are located in the tetraimine macrocyclic cavity, and a water molecule and a perchlorate group are separately coordinated to the metal ions on the same side of the ring. Coordination geometry around each metal is approximately square pyramidal. ESMS spectra were used to characterize the complexes and isotopic distributions were investigated. [ABSTRACT FROM AUTHOR]

The Gd atom in the title compound, [Gd(C33H39N11)]Cl3·3H2O, lies on a position of 32 point symmetry and exhibits a tricapped trigonal prismatic coordination geometry. A twofold rotation axis passes through the coordinated N atom and the opposite C atom of the pyridyl ring of the ligand, while a threefold rotation axis passes through the aliphatic N atom. The Cl atom and O atom of the uncoordinated water mol­ecule both lie on twofold rotation axes. [ABSTRACT FROM AUTHOR]

The dimeric title complex, [Ho2(CH3COO)6(C12H8N2)2], lies about a centre of symmetry. Each cation is coordinated by a chelating 1,10-phenanthroline and two chelating acetato ligands, one of which also bridges the two Ho atoms. Two other bridging acetate ligands complete the coordination of the nine-coordinate holmium(III) atoms. [ABSTRACT FROM AUTHOR]

In the asymmetric unit of the title compound, [LuIII(C26H34N6O2)(NO3)2]NO3·0.5H2O·0.25C4H8O2, there are two cations and two anions of the title complex, together with a water molecule and half a molecule of ethyl acetate. The Lu atom exhibits a nine-coordinate distorted tricapped trigonal-prismatic coordination geometry. The water molecule is disordered, with occupation factors of 0.4 and 0.6. [ABSTRACT FROM AUTHOR]

The title dinuclear complex, [Cu2(C12H17FN3O2)2](ClO4)2·CH4O, was synthesized by condensation between diethyl­ene­triamine and 2-form­yl-4-fluoro-6-hydroxy­methyl­phenol in the presence of copper(II). It contains two similar units, which are linked by Cu—O bonds. The approximate planes of the two units are parallel to each other, and π–π inter­action exists between the two units. [ABSTRACT FROM AUTHOR]

In the title complex, [Cd2(C24H26N4O2)(ClO4)2(H2O)2][Cd2(C24H26N4O2)(H2O)2](ClO4)2, the two distinct macrocycles adopt essentially flat structures. They each encapsulate two Cd atoms. One Cd coordination polyhedron, completed by a water O atom and a perchlorate O atom, is distorted octa­hedral, while the other is best described as a CdN2O3 square-based pyramid, with water in the apical site. Both dinuclear complexes are centrosymmetric. [ABSTRACT FROM AUTHOR]

The Gd atom in the title title complex, [Gd(NO3)2(C26H34N6O2)]NO3·H2O, exhibits a nine-coordinate distorted tricapped trigonal prismatic coordination geometry. The water molecule is disordered, with restrained occupancy factors of 0.4 and 0.6, with one component lying on a twofold rotation axis. [ABSTRACT FROM AUTHOR]