Damir A. Safin

FRET based tri-color emissive rhodamine–pyrene conjugate as an Al3+ selective colorimetric and fluorescence sensor for living cell imaging

A rhodamine-pyrene hybrid molecule acts as a colorimetric and fluorimetric sensor for Al(3+) through time dependent PET-CHEF and FRET processes associated with tri-color emission. Intracellular Al(3+) has been visualized through time dependent blue-green-red emission. The lowest limit of detection for Al(3+) is 0.02 μM.

The influence of the intramolecular hydrogen bond on the 1,3-N,S- and 1,5-O,S-coordination of N-phosphoryl-N′-(R)-thioureas with Ni(II) and Pd(II)

Reaction of the potassium salts of N-phosphorylated thioureas of common formula R1–N(H)–C(S)–N(H)–P(O)(OiPr)2 (HA) with NiII and PdII cations leads to [MA2] chelate complexes (M = NiII, R1 = p-MeOC6H4, p-BrC6H4, t-Bu, c-Hex; M = PdII, R = iPr). In both the NiII and PdII complexes, the metal center is found in a square-planar N2S2 environment formed by the CS sulfur atoms and the P–N nitrogen atoms of two deprotonated ligands A−. The PdII atoms in [PdB2] complexes with deprotonated thioureas of common formula R2–C(S)–N(H)–P(O)(OiPr)2 (HB) (R2 = Et2N, morpholine-N-yl) are coordinated in a square-planar fashion by the CS sulfur atoms and the PO oxygen atoms of two anionic ligands. Molecular structures of four complexes [M(A-N,S)2] (M = NiII, R1 = p-MeOC6H4, p-BrC6H4, t-Bu; M = PdII, R1 = iPr) and the palladium(II) 1,5-O,S-chelate of formula [Pd(B-O,S)2] (R2 = morpholine-N-yl) were elucidated by X-ray diffraction.

Solid-state thermo- and photochromism in N,N′-bis(5-X-salicylidene)diamines (X = H, Br)

Sixteen N,N′-bis(salicylidene)diamines of common formula (o-OHC 6H 4CN-) 2Z [Z = o-C 6H 4 (1a), m-C 6H 4 (2a), p-C 6H 4 (3a), O (4a), CH 2(p-C 6H 4) 2 (5a), O(p-C 6H 4) 2 (6a), S(p-C 6H 4) 2 (7a), SO 2(p-C 6H 4) 2 (8a)] and N,N′-bis(5-bromosalicylidene)diamines of common formula (2-OH-(5-Br)C 6H 3CN-) 2Z [Z = o-C 6H 4 (1b), m-C 6H 4 (2b), p-C 6H 4 (3), O (4b), CH 2(p-C 6H 4) 2 (5b), O(p-C 6H 4) 2 (6b), S(p-C 6H 4) 2 (7b), SO 2(p-C 6H 4) 2 (8b)] have been synthesized and characterized by elemental analysis, X-ray powder diffraction, NMR, diffuse reflectance, Raman, IR and fluorescence spectroscopy. Molecular structures of 2a, 6a, 7a, 8a and 4b were elucidated by single crystal X-ray diffraction. Their structures are stabilized by two intramolecular hydrogen bonds and weak intermolecular π⋯π stacking interactions. All molecules are thermochromic, while molecules 2a and 2b exclusively display photochromism upon irradiation at 450 and 365 nm, respectively, which is reversible and exhibits relatively slow thermal relaxation.

Competitive bulk liquid membrane transport of some metal ions using RC(S)NHP(S)(OiPr)2 as ionophores. Unusual supramolecular “honeycomb” aggregate of the polynuclear copper(I) complex of H2NC(S)NHP(S)(OiPr)2

Competitive transport experiments involving metal ions from an aqueous source phase through a chloroform membrane into an aqueous receiving phase have been carried out using a series of N-(thio)phosphorylated (thio)amide and thiourea ligands as ionophores in the organic phase. The source phase contained equimolar concentrations of Co(II), Ni(II), Cu(II), Zn(II), Ag(I), Cd(II) and Pb(II) with the source and receiving phases being buffered at different pH. Good transport properties were observed for Ag(I) in the case of (13). The best extraction properties have been shown by (3)L(1), (3)L(8), (2)L(7), (3)L(9) and (3)L(11) which contain an unsubstituted nitrogen atom at the C[double bond, length as m-dash]S groups ((3)L(1) and (3)L(9)), or a third nitrogen atom, capable of participating in additional coordination ((3)L(8), (2)L(7) and (3)L(11)). Reaction of Cu(NO(3))(2).6H(2)O with the potassium salt of the N-thiophosphorylated thiourea NH(2)C(S)NHP(S)(OiPr)(2) formed a new supramolecular Cu(I) complex, [{Cu(6)((2)L(1))(6)}{Cu(3)((2)L(1))(3)}.4Me(2)CO] that contains both trinuclear and hexanuclear forms in its solid state structure, and in solution.

Unprecedented trinuclear Ag(I) complex with 2,4,6-tris(2-pyrimidyl)-1,3,5-triazine as an efficient catalyst for the aziridination of olefins.

An unprecedented trinuclear heteroleptic Ag(I) complex was isolated using a stable multidentate 2,4,6-tris(2-pyrimidyl)-1,3,5-triazine (TPymT) ligand. The obtained compound is an efficient catalyst for the direct aziridination of terminal olefins.

Competitive bulk liquid membrane transport and solvent extraction of some metal ions using RC(S)NHP(X)(OiPr)2 (X = O, S) as ionophores. Formation of the polynuclear complex of [Ag(NC–NP(S)(OiPr)2)]n

Competitive transport experiments involving metal ions from an aqueous source phase through a chloroform membrane into an aqueous receiving phase have been carried out using a series of N-(thio)phosphorylated (thio)amide and thiourea ligands as the ionophore present in the organic phase. The source phase contained equimolar concentrations of Co(II), Ni(II), Cu(II), Zn(II), Ag(I), Cd(II) and Pb(II) with the source and receiving phases being buffered at a number of different pHs. Solvent extraction properties of the ligands towards the same metal cations under the same experimental conditions as for the transport were also studied. All ligands demonstrated 100% extraction of Ag(I). Reaction of AgNO(3) with the potassium salt of the N-thiophosphorylated thiourea NH(2)C(S)NHP(S)(OiPr)(2) gave a new supramolecular Ag(I) complex, [AgZ](n) (Z = {N[triple bond]C-NP(S)(OiPr)(2)}(-)) that contains both tri- and tetracoordinated Ag(I). The novel polynuclear Ag(I) complex [AgZ](n) described and structurally characterized by single crystal X-ray diffraction has no precedent.

Crown ether-containing N-salicylidene aniline derivatives: synthesis, characterization and optical properties

15-Crown-5 ether-containing N-salicylidene aniline derivatives of the common formula benzo-15-crown-5-NCH–(2-OH-aryl) [aryl = C6H4 (1), 5-ClC6H3 (2), 5-BrC6H3 (3), C10H6 (4)] have been synthesized and characterized by elemental analysis, NMR, diffuse reflectance, fluorescence, IR and Raman spectroscopies. The crystal structure of 1, elucidated by X-ray diffraction, is stabillized by an intramolecular hydrogen bond and intermolecular π⋯π stacking interactions. Molecules 1–3 are thermochromic and show the presence of a mixture of enol and cis-keto forms in the solid state at room temperature. Compound 1 displays photochromism upon irradiation at 546 nm, which is reversible and exhibits relatively quick back thermal relaxation.

Solvent-induced 1,3-N,S- vs. 1,5-S,S′-coordination in the NiII complex [Ni{p-Me2NC6H4NHC(S)NP(S)(OiPr)2}2]

Reaction of the deprotonated N-thiophosphorylated thiourea p-Me2NC6H4NHC(S)NHP(S)(OiPr)2 (HL) with NiCl2 leads to violet [Ni(L-1,3-N,S)2] or dark violet [Ni(L-1,5-S,S′)2]·(CH3)2CO crystals that were isolated by recrystallization from a mixture of CH2Cl2 or acetone, respectively, and n-hexane.

A Composite of Complex and Chemical Hydrides Yields the First Al‐Based Amidoborane with Improved Hydrogen Storage Properties

The first Al-based amidoborane Na[Al(NH2 BH3 )4 ] was obtained through a mechanochemical treatment of the NaAlH4 -4 AB (AB=NH3 BH3 ) composite releasing 4.5 wt % of pure hydrogen. The same amidoborane was also produced upon heating the composite at 70 °C. The crystal structure of Na[Al(NH2 BH3 )4 ], elucidated from synchrotron X-ray powder diffraction and confirmed by DFT calculations, contains the previously unknown tetrahedral ion [Al(NH2 BH3 )4 ](-) , with every NH2 BH3 (-) ligand coordinated to aluminum through nitrogen atoms. Combination of complex and chemical hydrides in the same compound was possible due to both the lower stability of the AlH bonds compared to the BH ones in borohydride, and due to the strong Lewis acidity of Al(3+) . According to the thermogravimetric analysis-differential scanning calorimetry-mass spectrometry (TGA-DSC-MS) studies, Na[Al(NH2 BH3 )4 ] releases in two steps 9 wt % of pure hydrogen. As a result of this decomposition, which was also supported by volumetric studies, the formation of NaBH4 and amorphous product(s) of the surmised composition AlN4 B3 H(0-3.6) were observed. Furthermore, volumetric experiments have also shown that the final residue can reversibly absorb about 27 % of the released hydrogen at 250 °C and p(H2 )=150 bar. Hydrogen re-absorption does not regenerate neither Na[Al(NH2 BH3 )4 ] nor starting materials, NaAlH4 and AB, but rather occurs within amorphous product(s). Detailed studies of the latter one(s) can open an avenue for a new family of reversible hydrogen storage materials. Finally, the NaAlH4 -4 AB composite might become a starting point towards a new series of aluminum-based tetraamidoboranes with improved hydrogen storage properties such as hydrogen storage density, hydrogen purity, and reversibility.

First evidence of thermo- and two-step photochromism of tris-anils

Seven N,N′,N′′-tris(salicylidene)triamines of common formula N(CH2CH2NCH–aryl) [aryl = 2-OH-C6H4 (1), 2-OH-(5-Cl)C6H3 (2), 2-OH-(5-Br)C6H3 (3), 2,5-(OH)2C6H3 (4), 2,4-(OH)2C6H3 (5), 2,3,4-(OH)3C6H2 (6) and 2-OH-C10H6 (7)] have been synthesized and characterized by elemental analysis, X-ray powder diffraction, NMR, diffuse reflectance, Raman and fluorescence spectroscopy. All the tris-anils are thermochromic. 4 exclusively displays photochromism upon irradiation at 365 nm with a unique two-step back thermal relaxation, with kinetic constants kI = 1.0 × 10−5 s−1 and kII = 4.0 × 10−5 s−1 for the first and second steps, respectively. The origin of the observed photochromism is due to a cis/trans-keto isomerization.