Small molecule fluorescent probes of protein vicinal dithiols

The vicinal dithiol motif is widely present in proteins, and is critical for proteins’ structures and functions.In recent years, a variety of fluorescent probes with high specificity and outstanding optical properties for sensing protein vicinal dithiols have been developed. In this review, we summarized the fluorescent probes of protein vicinal dithiols in literature. These probes are classified into four types based on their acceptor sites, i.e., biarsenical probes, monoarsenical probes, dimaleimide probes and diacrylate probes.Through analyzing the properties of different probes, we expect that this review would help readers further understand the structural factors of these probes and provide the design strategy for novel fluorescent probes with improved properties.

MAGNETIC INVESTIGATION OF THE NICKEL COMPLEXES OF MULTI－SULFUR 1．2－DITHIOLATES

The magnetic susceptibility of (Bu4N)(NI(MEDT)2) and (Bu4N)(Ni(PHDT)2)(MEDT:5-methyl-6-hydro-1, 4-dithiin-2, 3-dithiolate, PHDT: 5-phenyl-6-hydro-1.4-dithiin- 2,3-dithiolate) was measured in the temperature range of 75-300K. The magnitudeof magnctic moments is consistent,with a doublet state arising from Ni(Ⅲ).Antiferromagnetic properties were discussed in consideration of molecularstructure.

Synthesis and Structure of Iron Complex with 1,2-Dithiolate-1,2-dicarba-closo-dodecaborane [Li(THF)_4][Fe(S_2C_2B_10H_10)_2(THF)]

The crystal of complex [Li(THF)4][Fe(S2C2B10H10)2(THF)] 3 belongs to monoclinic, space group P21 with a = 11.964(2), b = 16.527(3), c = 12.554(3) ? = 108.70(3)? V = 2351.3(8) 3, Z = 2, Mr = 835.95, Dc = 1.181 g/cm3, (MoK? = 5.30 cm1, F(000) = 874, R = 0.0622 and Rw = 0.1538 for 1641 observed reflections with I > 2(I). The ionic complex of 3 contains the square pyramidal anion of [Fe(S2C2B10H10)2(THF)] and the tetrahedral cation of [Li(THF)4]+. The iron is 5-coordinated and located in the square pyramidal configuration. The iron atom and the four sulfur atoms are almost coplanar. The Lithium atom is coordinated with four oxygen atoms of four THF molecules and located in a tetrahedral configuration.

THE SYNTHESIS OF 4，5－BIS（4＇－BROMOBENZYLTHIO）－1，3－DITHIOLE－2－THIONE WITH ONE DIMENSIONAL INTERMOLECULAR INTERACTIONS

The title compound BBBT-Dry (C17H12Br2S5, Mr=536.42) has been synthesized and its structure feature has been described. BBBT-DTT is characterized by one dimensional chains formed by S…S (head to head) and Br…Br (tail to tail) intermolecular interactions.

Synthesis and Crystal Structure of (Bu_4N)_2Hg(i-mnt)_2

The synthesis and the crystal structure of the title compound (Bu4N)(2)Hg(S2C=C(CN)(2))(2) 1 is reported herein. The crystal is attributed to trielinic system and space group P-1, fw=965.88. The crystal lattice parameters are a=9.45(1), b=15.827(2), c=17.619(2)Angstrom, alpha =108.12(2), beta =99.54(2), gamma =97.60(2)degrees, V=2421.9(8)Angstrom, mu (MoKalpha)=3.390mm(-1), Z=2, D-c=1.324g.cm(-3), F(000)=996, R=0.054, wR=0.058.

Coupling effects in QD dimers at sub-nanometer interparticle distance

Currently,intensive research efforts focus on the fabrication of meso-structures of assembled colloidal quantum dots(QDs)with original optical and electronic properties.Such collective features originate from the QDs coupling,depending on the number of connected units and their distance.However,the development of general methodologies to assemble colloidal QD with precise stoichiometry and particle-particle spacing remains a key challenge.Here,we demonstrate that dimers of CdSe QDs,stable in solution,can be obtained by engineering QD surface chemistry,reducing the surface steric hindrance and favoring the link between two QDs.The connection is made by using alkyl dithiols as bifunctional linkers and different chain lengths are used to tune the interparticle distance from few nm down to 0.5 nm.The spectroscopic investigation highlights that coupling phenomena between the QDs in dimers are strongly dependent on the interparticle distance and QD size,ultimately affecting the exciton dissociation efficiency.

Reactions of a 16-electron Cp*Co half-sandwich complex containing a chelating 1,2-dicarba-closo-dodecaborane-1,2-dithiolate ligand with alkynones HC≡C-C(O)R (R=OMe,Me,Ph)

The reaction of the 16e half-sandwich complex Cp*Co(S2C2B10H10) (1) (Cp* = pentamethylcyclopentadienyl) with excess methyl acetylene monocarboxylate, HC≡C-CO2Me, affords the 18e complexes 2-6. Compound 2 bears a B-CH2 unit in which B-substitution occurs in the B(3)/B(6) position of the ortho-carborane cage. Complexes 3-6 are geometrical isomers, in which the alkyne is twofold inserted into one of the Co-S bonds in all the four possible ways. Treatment of 1 with excess 3-butyn-2-one or phenyl ethynyl ketone, HC≡C-C(O)R (R = Me, Ph), at ambient temperature leads to the 18e complexes 7-10, respectively, with two alkynes inserted into one of the Co-S bonds. All the new complexes were fully characterized by spectroscopic techniques and elemental analysis. The solid-state structures of 2, 3, 5, 7, 8, 9 and 10 were further characterized by X-ray structural analysis.

Cluster-cracking Reaction, a New Method to Synthesize Unsymmetrical Dithiolate Complexes for the Study of Third-Order Nonlinear Optical Properties

A new cluster-cracking method to synthesize dithiolate metal complexes was reported and four unsymmetric complexes with formula (Me4N)(2)[M(Ln)(SPh)(2)] (M = Cd and Zn, L1 = dmit = 1, 3-dithiole-2-thione-4, 5-dithiolate, L2 = dmid = 1, 3-dithiole-2-one-4, 5-dithiolate, SPh = thiophenolate) (1-4) were characterized by, elemental analysis, ER, UV NMR spectra and so on. The advantages of this method am summarized in two aspects: (1) the preparation is very convenient; (2) the reaction usually completed giving the product with high,purity. The crystal structure of 1 showed that the bond distances of Cd(II) to the sulfur of the thiophenolate group are shorter than those of Cd(II) to the sulfur of dmit, so that the thiophenolate group does not be replaced in the reaction and the mixed ligand complexes are the dominant products. The dmit complexes showed well third-order NLO properties, but not of the dmid complexes, although druid is an analogue to dmit.

Hydrothermal Synthesis, Crystal Structure and Optical Properties of [M（en）3]（ndt）·H2O （M=Ni^Ⅱ, Co^Ⅱ, Mn^Ⅱ and ndt= 1,5-Naphthalenedithiolate）

Three novel compounds [Ni（en）3]（ndt）·H2O （1）, [Co（en）3]（ndt）·H2O （2） and [Mn（en）3]（ndt）·H2O （3） （en= ethylenediamine, ndt= 1,5-naphthalenedithiolate） have been synthesized under hydrothermal conditions, The structures were characterized by single crystal X-ray diffraction and all belong to monoclinic space group Cc. The [M（en）3]^2＋ cations （M=Ni^Ⅱ, Co^Ⅱ, Mn^Ⅱ）, ndt anions and crystallized water molecules assemble an iso-structural three-dimensional network through H-bonding interactions. Optical absorption properties and band gaps of such three compouds were determined with UV/Vis/NIR diffuse reflectance spectra.