120-70-7

Basic information

• Product Name: N,N'-BIS(SALICYLIDENE)-1,3-PROPANEDIAMINE
• Synonyms: 2-((E)-[((E)-3-([(E)-(2-Hydroxyphenyl)methylidene]amino)propyl)imino]methyl)phenol;alpha,alpha'-(Trimethylenedinitrilo)di-o-cresol;Disalicylicenepropanediamine;Disalicylidene-1,3-propanediamine;disalicylidenepropandiamine;Disalicylidenepropanediamine;o-Cresol, alpha,alpha'-(trimethylenedinitrilo)di-;Phenol, 2,2'-[1,3-propanediylbis(nitrilomethylidyne)]bis-
• CAS NO: 120-70-7
• Molecular Formula: C₁₇H₁₈N₂O₂
• Molecular Weight: 282.34
• EINECS: 204-418-6
• Mol File: 120-70-7.mol
• Article Data: 77

Chemical Properties

• Melting Point: 51-53°C
• Boiling Point: 510.1°Cat760mmHg
• Flash Point: 113 °C
• Appearance: /
• Density: 1.288g/cm³
• Storage Temp.: Sealed in dry,Room Temperature
• Solubility: almost transparency in Toluene
• PKA: 12.55±0.50(Predicted)
• BRN: 2057483
• CAS DataBase Reference: N,N'-BIS(SALICYLIDENE)-1,3-PROPANEDIAMINE(CAS DataBase Reference)
• NIST Chemistry Reference: N,N'-BIS(SALICYLIDENE)-1,3-PROPANEDIAMINE(120-70-7)
• EPA Substance Registry System: N,N'-BIS(SALICYLIDENE)-1,3-PROPANEDIAMINE(120-70-7)

Safety Data

• Statements: 36/37/38
• Safety Statements: 26-36-24/25-22
• WGK Germany: 3
• Hazardous Substances Data: 120-70-7(Hazardous Substances Data)

Usage

Uses

N,N′-Bis(salicylidene)-1,3-propanediamine has been used in the synthesis of:new trinuclear heterometallic Cu(II)-Mn(II) complexesmononuclear nickel complex, NiL (LH2 = N,N′-bis(salicylidene)-1,3-diaminopropane)

General Description

N,N′-Bis(salicylidene)-1,3-propanediamine is a di-Schiff base ligand.

Upstream product

• 90-01-7 salicylic alcohol 
• 109-76-2 Trimethylenediamine 
• 118-93-4 o-hydroxyacetophenone 
• 90-02-8 salicylaldehyde 
• 89-95-2 2-methyl-benzyl alcohol 

Downstream Products

• 110305-16-3 (CH₃)3SiO^(1-)*Al⁽³⁺⁾*(C₁₇H₁₆O₂N₂)^(2-)=(CH₃)3SiOAl(C₁₇H₁₆O₂N₂) 
• 1235146-62-9 C₃₁H₂₇N₂O₄P*ClH 
• 389089-66-1 C₂₉H₂₆B₂N₂O₃ 

Relevant articles and documents

Selective dopamine chemosensing using silver-enhanced fluorescence

Condensation product of salicylaldehyde and 1,3 propylenediamine becomes a diiminic Schiff base, which is oxidized by AgNO3 in alkaline solution, and in turn, stable Ag(0) is produced at room temperature. Under this condition, the solution exhibits intense silver nanoparticle enhanced fluorescence (SEF) with the em at 412 nm. Dopamine is selectively detected down to the nanomolar level via exclusive fluorescence quenching of the SEF. Dopamine-infested solution regains the fluorescence [i.e., SEF in the presence of Hg(II) ions]. Thus dopamine and Hg(II) in succession demonstrate "turn off/on" fluorescence due to the change in the scattering cross section of Ag(0) and gives a quantitative measure of dopamine in real samples. The proposed method is free from interferences of common biocompetitors.

Hetero-metallic trinuclear nickel(II)-cadmium(II) complexes of a salicylaldimine ligand with thiocyanate, cyanate and azide ions: Isolation of a pair of polymorphs with thiocyanate ion

Four new trinuclear hetero-metallic nickel(II)-cadmium(II) complexes [(NiL)2Cd(NCS)2] (1A and 1B), [(NiL)2Cd(NCO) 2] (2) and [(NiL)2Cd(N3)2] (3) have been synthesized using [NiL] as a so-called "ligand complex" (where H2L = N,N′-bis(salicylidene)-1,3-propanediamine) and structurally characterized. Crystal structure analyses reveal that all four complexes contain a trinuclear moiety in which two square planar [NiL] units are bonded to a central cadmium(II) ion through double phenoxido bridges. The Cd(II) is in a six-coordinate distorted octahedral environment being bonded additionally to two mutually cis nitrogen atoms of terminal thiocyanate (in 1A and 1B), cyanate (in 2) and azide (in 3). Complexes 1A and 1B have the same molecular formula but crystallize in very different monoclinic unit cells and can be considered as polymorphs. On the other hand, the two isoelectronic complexes 2 and 3 are indeed isomorphous and crystallize only in one form. Their conformation is similar to that observed in 1A.

The impact of anion-modulated structural variations on the magnetic coupling in trinuclear heterometallic CuII-CoII complexes derived from a salen-type Schiff base ligand

Three new trinuclear heterometallic [(CuIIL)2Co IIX2] complexes [H2L = N,N′- bis(salicylidene)-1,3-propanediamine and X = thiocyanate (1), benzoate (2), or azide (3)] have been synthesized by reacting the metalloligand [CuL] with Co(ClO4)2·6H2O and the NH 4+ or Na+ salt of the corresponding anion in methanol. Structural characterization reveals that the central CoII ion is connected to two terminal metalloligands through μ1,1- diphenoxido bridges in all three complexes. However, two monodentate thiocyanato ions, which are mutually cis coordinated to the Co atom in 1, generate a "bent" structure, whereas the trans-coordinated syn-syn bridging benzoato (1κO:2κO′) and the end-on bridging azido (μ1,1) coligands in 2 and 3, respectively, produce linear structures. The changes in the number and nature of the bridges with a shortening of the distances between the metal centers leads to a concomitant decrease of the average CuII-O-CoII bridging angle from 99.3(2) to 97.1(4) and 91.5(1)° for 1, 2 and 3, respectively. Variable-temperature magnetic susceptibility measurements show the presence of a dominant antiferromagnetic coupling between the Cu-Co pairs in all three complexes. However, a steady decrease of the magnitude of the exchange coupling constant (JCu-Co) is observed from -33.4 (for 1) to -11.4 (for 2) and -2.15 cm-1 (for 3). This trend suggests that larger Cu-O-Co angles are associated with stronger antiferromagnetic coupling. Anion-mediated geometrical variations generate three heterometallic complexes with distinct trinuclear Cu2Co cores as a result of different diphenoxido bridging angles between the CuII and CoII ions. Magnetic studies reveal decreased antiferromagnetic exchange interactions associated with a decrease of this bridging angle. Copyright

Structure and spin-spin interactions in a linear trinuclear Ni(II) complex

[Ni3(C2H3O2)2(C 3H8NO)2L2] [(L=N,N'-1,3-propyl-disalicylaldimine), (C2H3O2)=acetate, (C3H8NO)=hydroxymethyl-dimethylamine] has been synthesized and ils crystal structure determined, [C44H54N6O10Ni3], triclinic, space group P1?, a = 9.560(1), b = 10.681(1), c = 12.200(1) ?, α = 112.17(1), β = 101.25(1), γ = 90.32(1)°, V = 1127.3 ?3 Z = 1. The molecule is linearly trinuclear with octahedral coordination of each nickel ion. The Ni-Ni distance is 3.048(1) ?. Each nickel(II) atom is in an octahedral coordination. Magnetic susceptibility measurements in the range 4.2 1 = -2.2 cm-1) and between the terminal Ni atoms (J2 = -1.7 cm-1).

Rare trinuclear NiII2MII complexes (MII?=?Mn, Fe and Co) with a reduced Schiff base ligand: Synthesis, structures and magnetic properties

Three new trinuclear hetero-metallic NiII2MII complexes with MII = Mn, Fe and Co have been synthesized using a [NiLR] “metalloligand”, where H2LR = N,N′-bis(2-hydroxybenzyl)-1,3-propanediamine. All complexes have been characterized by elemental analysis, spectroscopic methods, single crystal XRD and magnetic and electrochemical studies. In the three complexes, in addition to the double phenoxido bridges, the two terminal NiII atoms are linked to the central MII [M = Mn(1), Fe(2) and Co(3)] ion by means of a bridging carboxylato co-anion, giving rise to a linear NiII-MII-NiII structure. Variable temperature magnetic susceptibility measurements show the presence of weak ferromagnetic and antiferromagnetic exchange interactions mediated through the double phenoxido bridges with J values of +8.5 and ?3.0 cm?1 for complexes 1 and 2, respectively. Compound 3 shows the presence of antiferromagnetic interactions. Cyclic voltammetry shows a common quasi-reversible one electron oxidation corresponding to the Ni(II)/Ni(III) process in 1–3 and an irreversible M(II)/M(III) oxidation for Mn(1) and Fe(2).

The effect of electronegativity upon the coordination sphere; heterodinuclear Ni(II) complexes with ONNO type Schiff bases, octahedral, square pyramidal and square planar coordination of Ni(II)

NiL.MX2 heterodinuclear complexes with a nuclear structure of NiII-MII (M = Zn, Cd, X = Cl, Br, I) were prepared in the dioxane medium by the use of an ONNO type ligand, Bis-N,N′(salicylidene)-1,3-propanediamine (LH2). The complexes prepared were characterized by the use of infrared (IR) spectroscopy, thermogravimetry (TG), semi-micro nitrogen, metal and halogen analysis. The molecular structures and unit cell properties of the compounds were elucidated by the X-ray diffraction (XRD) method. In parallel to the literature, MX2 group was observed to form μ? bridges with the phenolic oxygens of the organic ligand. The coordination sphere of NiL heterodinuclear complex in NiL group was observed to change depending upon the electronegativities of the atoms in MX2 group. The electronegativities of the atoms in the MX2 group affect the coordination sphere of NiL group of the heterodinuclear complex, and in parallel with the electronegativities of the atoms in MX2 group, it was observed that NiL unit coordinated the solvent molecules and the coordination sphere changed. In addition to this, the coordination bonds get smaller as the number of donor atoms nearby NiL decreased. Using Gaussian 09 software, the theoretical bond lengths and bond angles were calculated and compared with the experimental data. With Gaussian 09 software, it was determined how the occupancy levels of d orbitals of the metal atoms changed by coordination of Ni(II) ion. Also, the change of the differences between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) levels of the complexes was monitored.

Playing with different metalloligands [NiL] and Hg to [NiL] ratios to tune the nuclearity of Ni(II)-Hg(II) complexes: Formation of di-, tri-, hexa- and nona-nuclear Ni-Hg clusters

Five new hetero-metallic nickel(II)-mercury(II) complexes, [(NiL1)HgCl2] (1), [(NiL1)2HgCl2] (3), [(NiL1)2Hg(N3)2] (4), [{(NiL2)2Hg(N3)(μ1,1-N3)}2] (5) and [{(NiL2)2Hg(N3)(μ1,1-N3)HgCl2}2{Hg(N3)(μ1,1-N3)}] (6) have been synthesized by reacting metalloligands [NiL1] or [NiL2] (where H2L1 is N,N′-bis(salicylidene)-1,2-ethylenediamine and H2L2 is N,N′-bis(salicylidene)-1,3-propanediamine) with HgX2 (X- = Cl- or N3-) at different molar ratios. All five complexes have been characterised by X-ray single-crystal structural, elemental and spectroscopic analyses. In complex 1, the Hg(II) ion is coordinated to two phenoxido oxygen atoms of one [NiL1] moiety and two terminal chloride ions to form a NiHg dinuclear complex. In the trinuclear complexes 3 and 4, the central Hg(II) ion is coordinated by two terminal [NiL1] units through two phenoxido oxygens from each and two terminal chloride (in 3) or azide (in 4) ions. The centrosymmetric hexanuclear complex 5 consists of two trinuclear [(NiL2)2Hg(N3)(μ1,1-N3)] units, where the phenoxido bridges connect two terminal Ni(II) atoms of the trinuclear units. In these trinuclear units, one azido ligand adopts a μl,1-briding mode between Hg and Ni whereas the other one is terminal. In the nonanuclear complex 6, two tetranuclear [{(NiL2)2Hg(N3)(μ1,1-N3)}HgCl2] units are linked to a central Hg(II) positioned on a two fold axis, via chlorido, azido, and phenoxido bridges. The tetranuclear unit is formed by the addition of a HgCl2 molecule to a trinuclear [(NiL2)2 Hg(N3)(μ1,1-N3)] unit, similar to that present in 5. Complex 5 shows weak ferromagnetic interactions (J = +2.1 cm-1) between the two octahedral Ni(II) ions through double phenoxido bridges with a Ni-O-Ni bond angle of 95.87(11)°.

Synthesis, structure and magnetic properties of Ni(II)-Co(II) heterodinuclear complexes with ONNO type Schiff bases as ligands

Four new heterodinuclear Ni(II)-Co(II) complexes, NiL·CoCl 2·(DMF)2 (I), NiL·CoBr2· (DMF)2 (II), NiL′·CoCl2·(DMF) 2 (III) and NiLDM·CoCl2(DMF)2 (IV), have been prepared in non-aqueous DMF using the ONNO type Schiff bases N,N′-bis(2-hydroxyphenylidene)-1,3-propanediamine (LH2), N,N′-bis(2-hydroxyphenylidene)-1,4-butanediamine (L′H2) and N,N′-bis(2-hydroxyphenylidene)-2,2′-dimethyl-1,3-propanediamine (LDMH2), and the inorganic salts NiCl2 and CoCl 2. The complexes were characterized by elemental analysis, IR spectroscopy, thermogravimetry and X-ray diffraction. An XRD study revealed that the Ni(II) ion is situated at the center of a distorted octahedral coordination sphere formed by two iminic nitrogen and two phenolic oxygen atoms of the ONNO type Schiff base and two other oxygen atoms belonging to coordinated DMF molecules. On the other hand, the Co(II) ion is situated inside a distorted tetrahedral coordination sphere, members of which being the two halogen atoms and two oxygen atoms, bonded to form a μ-bridge. The magnetic susceptibility of the complexes was studied using a SQUID magnetometer between 2.0 and 300 K at B = 0.1 T, and the magnetization data were taken up to B = 7 T at T = 2.0 and 4.6 K. The exchange interaction between the metal centers is of a ferromagnetic nature (typically JCo-Ni/hc = +2 cm-1) and at low temperature single-ion zero-field splitting applies (DNi/hc = +8 cm-1, DCo/hc = +14 cm-1).

Polymorphism in hetero-metallic tri-nuclear CuII 2CdII complexes of salicylaldimine ligand: Structural analysis and theoretical study

Three new trinuclear hetero-metallic copper(II)-cadmium(II) complexes [(CuL)2Cd (NCS)2] (1A and 1B), [(CuL)2Cd(NCO) 2] (2) have been synthesized using [CuL] as so-called "ligand complex" (where H2L = N,N′-bis(salicylidene)-1,3- propanediamine) and structurally characterized. Crystal structure analyses reveal that all three complexes have trinuclear entity in which two square planar [CuL] units are bonded to a cadmium ion through double phenoxido bridges. The Cd(II) is in a six-coordinate distorted octahedral environment being bonded additionally to two mutually cis nitrogen atoms of terminal thiocyanate (in 1A and 1B) and cyanate (in 2). Complexes 1A and 1B have the same molecular formula but crystallize in different monoclinic unit cells (P21/c for 1A and P21/n for 1B) and can be considered as polymorphs. On the other hand, complex 2 is crystallized only in one form and its conformation is similar to that observed in 1A. A theoretical investigation shows that 1A is slightly more (2.25 kcal/mol) stable than 1B. However, in the crystal lattice, 1A establishes a C-H/π interaction while 1B interacts through a C-H···S hydrogen bond to form dimer and the more favorable dimerization energy in the later (ca. 3 kcal/mol) compensates the difference in the relative energy of the polymorphs. Complex 2 crystallizes only in one form and conformation of the molecule is similar to 1A. Analyses of the noncovalent interactions of 2 show a weakening of the dimerization energy compared to 1A or 1B. Moreover, the H-bonding interaction that facilitates the formation of 1B is unlikely to be established in 2. Therefore this polymorph is not isolated.

Isolation of two different Ni2Zn complexes with an unprecedented cocrystal formed by one of them and a "coordination positional isomer" of the other

A new homometallic trinuclear Ni(II) complex [(NiL)2Ni(NCS) 2] (1) and three heterometallic trinuclear Ni(II)-Zn(II)-Ni(II) complexes [(NiL)2Zn(NCS)2] (2), [(NiL)2Zn(NCS) 2(CH3OH)2]·2CH3OH (3) and {[(NiL)2Zn(NCS)2(CH3OH)2]} {[(NiL)2Zn(NCS)2]} (4) have been synthesized by using the "complex as ligand" approach with the "metalloligand" [NiL] (H2L = N,N′-bis(salicylidene)-1,3-propanediamine) and thiocyanate in different ratios. All the complexes have been structurally and magnetically characterized. In the isomorphous complexes 1 and 2, the two terminal square planar Ni atoms and the central octahedral nickel atom (in 1) or zinc atom (in 2) are arranged in a bent structure where two cis κN-SCN- thiocyanate ions are coordinated to the central atom. The chemical composition of 3 is very similar to that of 2 but, in 3, the central Zn atom is tetrahedral and the κN-SCN- thiocyanate ions occupy an axial position of each terminal nickel atom (which now are octahedral with the sixth position occupied by a methanol molecule). Complex 4 consists of two closely related trinuclear units 4A and 4B. In 4A, the coordination environments of the metals are identical to those of 3 whereas 4B is a "coordination position isomer" of complex 2 with the central square pyramidal Zn and one of the terminal square pyramidal Ni atoms coordinated by two κN-SCN- thiocyanate ions. Complex 4 is a unique example of a cocrystal formed by two similar trinuclear units (4A and 4B) where 4A is identical to an existing complex (3) and 4B is a "coordination position isomer" of another existing complex (2).

Diiminic Schiff bases: An intriguing class of compounds for a copper-nanoparticle-induced fluorescence study

The condensation products of salicylaldehyde and different diamines constitute an important class of diiminic Schiff bases (DSBs). This class of compounds has been rediscovered as reducing as well as capping agents under UV irradiation. UV irradiation of alkaline DSB solutions in the presence of water-soluble copper salts has been employed to produce copper nanoparticles (CuNPs). Intriguing CuNP-stimulated fluorescence behavior of the solution has been observed. Depending upon the nature of the spacer in between two iminic bonds, fluorescence enhancement or quenching is observed. Such surprising fluorescence contrast has been ascribed to far-field radiation and lossy surface waves. Making light of things: UV irradiation of alkaline diiminic Schiff base (DSB) solutions in the presence of water-soluble copper salts has been employed to produce copper nanoparticles (CuNPs). Fluorescence enhancement of the exposed DSBs was observed in the presence of in situ produced Cu0 (see figure). Copyright

Synthesis, crystal structure, theoretical calculations and thermal characterization of two heterodinuclear NiII–ZnII complexes prepared from ONNO-type symmetrical Schiff base and its reduced derivative

Two complexes in NiII–ZnII heterodinuclear form were prepared in DMF medium by the use of an ONNO-type symmetrical Schiff base bis-N,N′(salicylidene)-1,3-diaminopropane (LH2) and the reduced derivative of this ligand bis-N,N′(2-hydroxybenzylidene)-1,3-diaminopropane (LHH2). The fact that the complexes are in [NiL·ZnCl2·DMF2] and [NiLH·ZnCl2·(DMF)2] stoichiometry was verified with elemental and thermogravimetric analyses and IR spectroscopy. The structures of the complexes were determined by the use of X-ray diffraction. The two complexes were very similar, almost isostructure, and it was observed that Ni(II) ions in both complexes coordinated with two phenolic oxygens and two iminic nitrogen of organic ligand and formed an octahedral coordination between two DMF molecules. On the other hand, the Zn(II) ion was observed to be located in a tetrahedral coordination sphere coordinated with two phenolic oxygens between two halides. Although the molecular structures of the complexes are very similar, their thermal properties are quite different from of each other. The decomposition of [NiL·ZnCl2·(DMF)2] was observed between 140 and 190?°C by the removal of coordinative DMF molecules, leaving a residue of a mixture of NiL and ZnCl2 behind. The complex of the reduced ligand [NiLH·ZnCl2·(DMF)2] was observed to be stable up to 250?°C. After this temperature, the coordinative DMF molecules rapidly leave the structure before the degradation of NiLH. That is why the activation energies of the thermal reactions were evaluated by the use of isothermal and nonisothermal kinetic models: Coats–Redfern, Ozawa, Ozawa–Flynn–Wall and Kissinger–Akahira–Sunose. Also the thermal differences between these two complexes were examined by the use of theoretical programs included in Gaussian 09 package. The ground-state energies calculations were carried out by the use of density functional theory method 631G(d) basis set. The calculated theoretical bond energies and angles were observed to be different compared with the experimental data. The HOMO and LUMO values of the complexes were also calculated. The difference between these two complexes was evaluated.

Salen and tetrahydrosalen derivatives act as effective inhibitors of the tumor-associated carbonic anhydrase XII - A new scaffold for designing isoform-selective inhibitors

Salen and tetrahydrosalen derivatives possess metal-chelating properties and have been used as ligands in organic synthesis and as scaffolds for developing therapeutic agents. Fourteen such compounds were synthesized in order to explore their ability to inhibit the zinc enzyme carbonic anhydrase (CA, EC 4.2.1.1). Human (h) isoforms hCA I, hCA II, hCA IX and hCA XII were included in the investigation. Several aliphatic and aromatic spacers were introduced between the two chelating groups from salen/tetrahydrosalen in order to explore a diverse chemical space for designing CA inhibitors, which incorporate both phenol and polyamine fragments in their molecule. Some of these compounds showed CA inhibitory activity in the low micromolar-nanomolar range and a pronounced selectivity for inhibiting an isoform over-expressed in hypoxic tumors, hCA XII, over hCA I, II and IX.

Functional model for catecholase-like activity: A mechanistic approach with manganese(III) complexes of salen type Schiff base ligands

Three new Mn(III) complexes [MnL1(OOCH)(OH2)] (1), [MnL2(OH2)2][Mn2L2 2(NO2)3] (2) and [Mn2L 21(NO2)2] (3) (where H 2L1 = H2Me2Salen = 2,7-bis(2-hydroxyphenyl)-2,6-diazaocta-2,6-diene and H2L2 = H2Salpn = 1,7-bis(2-hydroxyphenyl)-2,6-diazahepta-1,6-diene) have been synthesized. X-ray crystal structure analysis reveals that 1 is a mononuclear species whereas 2 contains a mononuclear cationic and a dinuclear nitrite bridged (μ-1κO:2κO′) anionic unit. Complex 3 is a phenoxido bridged dimer containing terminally coordinated nitrite. Complexes 1-3 show excellent catecholase-like activity with 3,5-di-tert-butylcatechol (3,5-DTBC) as the substrate. Kinetic measurements suggest that the rate of catechol oxidation follows saturation kinetics with respect to the substrate and first order kinetics with respect to the catalyst. Formation of bis(μ-oxo)dimanganese(III,III) as an intermediate during the course of reaction is identified from ESI-MS spectra. The characteristic six line EPR spectra of complex 2 in the presence of 3,5-DTBC supports the formation of manganese(II)-semiquinonate as an intermediate species during the catalytic oxidation of 3,5-DTBC.

Structure of μ-oxo-bis{{2,2′-[propane-1,3-diylbis (aminomethyl)]diphenolato}oxorhenium(V)}

In the title compound, C34H40N407Re 2, each of the two Re(V) atoms is hexacoordinated by two amine nitrogens, two phenol oxygens, and two axial oxygens. The compound is a binuclear complex with an O=Re-O-Re=O backbone and nearly octahedral coordination geometry at each Re atom. The Re=O bond distance is 1.720(14) A and the Re-O bridge bond distance is 1.938(12) A. The equatorial plane Re-O bond distances are 1.992(14) and 2.012(13) A, whereas the Re-N bond distances are 2.129(15) and 2.187(16) A.

Synthesis, structure and magnetic properties of homotrinuclear Ni(II) complexes with asymmetric Schiff-base ligands

By using 1,3-propanediamine, 2-hydroxyacetophenone and salicylaldehyde an asymmetric ONNO type Schiff base, N(hydroxyphenylidene)-N′(2- hydroxyacetophenylidene)-1,3-propanediamine (H2metsalpn), has been prepared and isolated. This Schiff base has been reduced yielding N(2-hydroxybenzyl)-N′[1-(2-hydroxyphenyl)ethyl]-1,3-diaminopropane (H 2metsalpnH) These two ligands were used in preparing three trinuclear Ni(II) complexes with catena-[Ni3] structural motif, where DMF and carboxylato (formato, acetato, benzoato) ligands occur. These complexes were characterized by EA, IR, TG, DTA and MS data. The X-ray diffraction confirms that the Ni(II) central atoms are in a distorted octahedral coordination environment: the terminal centers possess {NiN2O 4} octahedral coordination sphere whereas the very central atom possesses {NiO6} chromophore. The coordinated DMF groups are liberated between 140-240 °C. The SQUID magnetometry confirms presence of weak exchange coupling of the antiferromagnetic nature, J/hc = -2 to -7 cm -1, with a moderate single-ion anisotropy reflected by the zero-field splitting D/hc = +4 to +7 cm-1.

Use of Cu(II)-di-Schiff bases as metalloligands in the formation of complexes with Cu(II), Ni(II) and Zn(II) perchlorate

One linear homo-metallic trinuclear [{CuL1(CH 3OH)}2Cu(ClO4)2] (1); five trinuclear hetero-metallic; bent [(CuL1)2Ni(H 2O)2](ClO4)2·H2O (2), linear [(CuL1)2Zn(ClO4)2] (3), bent [{CuL2(ClO4)}{CuL2(CH3OH)} Ni(CH3OH)2](ClO4)·(CH 3OH)·0.25(H2O) (4), triangular [(CuL 2){CuL2(CH3CN)}Ni(CH3CN) 2](ClO4)2 (5), triangular [(CuL 2)2Ni(H2O)2](ClO4) 2·3H2O (6) and one rare tetranuclear star-shaped [{CuL2(H2O)}2(CuL2)Zn](ClO 4)2·H2O (7) complexes have been synthesized by reacting the "metalloligand", [CuL1] or [CuL2] with corresponding metal perchlorate where the di-Schiff base ligands H2L1 = N,N′-bis(salicylidene)-1,3- propanediamine and H2L2 = (N,N′-bis(α- methylsalicylidene)-1,3-propanediamine. The structures of all the seven complexes have been determined by X-ray crystallography. Structural analysis shows that complexes 1-6 are discrete trinuclear species where phenoxido groups of two terminal "metalloligands" coordinate to a central Cu(II) in 1 or Ni(II) in 2, 4-6 or Zn(II) in 3. In 1 and 3 two trans axial positions of the central Cu(II) are weakly coordinated by the oxygen atoms of perchlorate anions and the molecules are linear. However, in 2, 4-6 two solvent molecules coordinate to the cis positions of the central Ni(II) to complete its distorted octahedral geometry that makes the molecules bent or triangular. On the other hand, complex 7 is a star-shaped tetranuclear species. In which three metalloligands bind a central Zn(II) ion through double phenoxido bridge.

Fluorescent organic nanoparticles (FONs) for selective recognition of Al3+: Application to bio-imaging for bacterial sample

The development of a novel chemo-sensor for the detection of Al3+ with high sensitivity in aqueous solution is widely considered an important research goal because of the importance of such probes in medicine, living systems and the environment. In this work, we describe a new fluorescent probe, a Schiff's base N,N′-propylenebis(salicylimine) (salpn) as fluorescent organic nanoparticles for Al3+. The study shows that salpn detects Al3+ with the detection limit as low as 1.24 × 10-3 mM, indicating that the chemo-sensor has high sensitivity in aqueous medium, and the fluorescence intensity increases with the increasing Al3+ concentration in the presence of the salpn-ONPs which act as chemo-sensors. The interference of common coexistent metal ions such as Mn2+, Mg2+, Co2+, Fe3+, Ni2+, Zn2+, Sr2+, Ag+, Sm3+, Al3+, Cd2+, Ba2+, Na+ and K+ was tested, showing that salpn-ONPs efficiently detect Al3+ ions with small interference from Cu2+ and Cr3+. Finally, the efficiency of salpn to as a fluorescent probe for Al ion in living systems was evaluated in Gram-negative and Gram positive bacteria, and con-focal laser scanning microscopy confirms its utility that this chemo-sensor efficiently detects Al3+ ion in Staphylococcus aureus enclosed by a single membrane.

H-bond assisted coordination bond formation in the 1D chains based on azido and phenoxido bridged tetranuclear Cu(II) complexes with reduced Schiff base ligands

Two new 1D chains [(CuL1R)2Cu2(N3)2(μ1,1,3-N3)2]n (1) and [{(CuL2R)2Cu2(N3)2(μ1,1,3-N3)2}·(CH3)2CO]n (2) based on rare μ1,1,3-N3 bridged tetranuclear Cu(II) complexes, have been synthesized using [CuL1R] and [CuL2R] as “metalloligands” [where H2L1R = N,N′-bis(2-hydroxybenzyl)-1,3-propanediamine and H2L2R = N,N′-bis(2-hydroxybenzyl)-1,2-ethylenediamine]. Both complexes have been characterized by elemental analysis, spectroscopic methods, single crystal XRD, and magnetic study. In case of chain 1, the basic building block is a centrosymmetric tetranuclear unit whereas for 2, it is an asymmetric tetranuclear unit containing two types of square pyramidal Cu(II) centers (terminal and central). The μ1,1-N3 bridged central copper atoms of one tetranuclear unit are connected weakly to the axial position of the terminal copper atoms of neibouring units via the azide ions forming a rare μ1,1,3-N3 bridged novel 1D polymeric chain structure. Variable temperature magnetic susceptibility measurements show the presence of an overall strong antiferromagnetic exchange interactions mediated through the double phenoxido bridges with J values of ?123.8 and ?144.6 cm?1 for 1 and 2, respectively.

Design of end-on cyanato bridged trinuclear Cu(II) Schiff base complex with salen type Schiff base ligand: synthesis, structural investigation and DFT study

One ONNO-donor tetradentate Schiff base ligand LH2 was derived from the condensation of salicylaldehyde and 1,3-diaminopropane and reacted with Cu(NO3)2·6H2O and NaNCO to yield one trinuclear complex with molecular formula [Cu3L2(μ1,1-NCO)2]. The synthesized complex was characterized by IR, UV–vis spectroscopy, and electrochemical analysis. Single-crystal X-ray diffraction study explores that the two terminal copper atoms adopt square pyramidal geometry, whereas the central copper atom situated at the inversion center is surrounded by four phenoxo oxygens and two end-on cyanato anions to adopt an octahedral geometry. The ONNO-tetradentate Schiff base ligand coordinates with the copper(II) ion via two oxygen atoms of the phenoxo-group and two nitrogen atoms from the imine moiety. A theoretical density functional theory (DFT) calculation was also carried out to supplement the experimental results. All the DFT calculations were done in gas phase.

Two new heterodinuclear Schiff base complexes: Synthesis, crystal structure and thermal studies

Two new heterodinuclear Schiff base complexes, [Hg(L)NiCl2(DMF)2] 1, and [Zn(L)NiCl2(DMF)2]2, where H2L= N,N'-bis(salicylidene)-1,3-diaminopropane and DMF = dimethylformamide have been synthesized and characterized using elemental analysis, IR spectroscopy, thermal analysis and X-ray diffraction. Structural studies on 1 and 2 reveal the presence of a heterodinuclear [NiIIHgII] unit and [ZnIINiII] in which the central metal ions are connected to each other by two phenolate oxygen bridges. For complex 1 the Ni(II) ion adopts an elongated octahedral geometry (NiN2O4) while the Hg(II) ion assumes a distorted tetrahedral arrangement (HgO2Cl2) whereas for complex 2 the Zn(II) ion adopts an elongated octahedral geometry (ZnN2O4) while the Ni(II) ion assumes a distorted tetrahedral arrangement (NiO2Cl2). There are intermolecular CAH.Cl AM interactions among the dinuclear complexes which are interconnected for 1 and 2. These intermolecular interactions result in the formation of a three dimensional structure for 1 and one dimensional zig-zag chains for 2.

Unprecedented structural variations in trinuclear mixed valence Co(ii/iii) complexes: Theoretical studies, pnicogen bonding interactions and catecholase-like activities

Three new mixed valence trinuclear Co(ii/iii) compounds cis-[Co3L2(MeOH)2(N3)2(μ1,1-N3)2] (1), trans-[Co3L2(H2O)2(N3)2(μ1,1-N3)2]·(H2O)2 (2) and [Co3LR2(N3)3(μ1,3-N3)] (3) have been synthesized by reacting a di-Schiff base ligand (H2L) or its reduced form [H2LR] (where H2L = N,N′-bis(salicylidene)-1,3-propanediamine and H2LR = N,N′-bis(2-hydroxybenzyl)-1,3-propanediamine) with cobalt perchlorate hexahydrate and sodium azide. All three products have been characterized by IR, UV-Vis and EPR spectroscopies, ESI-MS, elemental, powder and single crystal X-ray diffraction analyses. Complex 1 is an angular trinuclear species in which two terminal octahedral Co(iii)N2O4 centers coordinate to the central octahedral cobalt(ii) ion through μ2-phenoxido oxygen and μ1,1-azido nitrogen atoms along with two mutually cis-oxygen atoms of methanol molecules. On the other hand, in linear trinuclear complex 2, in addition to the μ2-phenoxido and μ1,1-azido bridges with terminal octahedral Co(iii) centres, the central Co(ii) is bonded with two mutually trans-oxygen atoms of water molecules. Thus the cis-trans configuration of the central Co(ii) is solvent dependent. In complex 3, the two terminal octahedral Co(iii)N2O4 centers coordinate to the central penta-coordinated Co(ii) ion through double phenoxido bridges along with the nitrogen atom of a terminal azido ligand. In addition, the two terminal Co(iii) are connected through a μ1,3-azido bridge that participates in pnicogen bonding interactions (intermolecular N-N interaction) as an acceptor. Both the cis and trans isomeric forms of 1 and 2 have been optimized using density functional theory (DFT) calculations and it is found that the cis configuration is energetically more favorable than the trans one. However, the trans configuration of 2 is stabilized by the hydrogen bonding network involving a water dimer. The pnicogen bonding interactions have been demonstrated using MEP surfaces and CSD search which support the counter intuitive electron acceptor ability of the μ1,3-azido ligand. Complexes 1-3 exhibit catecholase-like activities in the aerial oxidation of 3,5-di-tert-butylcatechol to the corresponding o-quinone. Kinetic data analyses of this oxidation reaction in acetonitrile reveal that the catecholase-like activity follows the order: 1 (kcat = 142 h-1) > 3 (kcat = 99 h-1) > 2 (kcat = 85 h-1). Mechanistic investigations of the catalytic behaviors by X-band EPR spectroscopy and estimation of hydrogen peroxide formation indicate that the oxidation reaction proceeds through the reduction of Co(iii) to Co(ii). This journal is

Influence of the central metal ion in controlling the self-assembly and magnetic properties of 2D coordination polymers derived from [(NiL)2M]2+ nodes (M = Ni, Zn and Cd) (H2L = salen-type di-Schiff base) and dicyanamide spacers

Three new 2D coordination polymers (CPs) 2∞[(NiL)2Ni(μ1,5-N(CN)2)2]n (1), 2∞[(NiL)2Cd(μ1,5-N(CN)2)2]n (2) and 2∞[(NiL)2Zn(μ1,5-N(CN)2)2]n (3) have been synthesized by reacting a [NiL] "metalloligand" (where H2L = N,N′-bis(salicylidene)-1,3-propanediamine) with three different metal(ii) (Ni, Cd and Zn) perchlorates and sodium dicyanamide, with identical molar ratios of the reactants. All three products have been characterized by IR and UV-Vis spectroscopies, elemental analyses, powder and single crystal X-ray diffraction and variable temperature magnetic measurements. The isomorphous compounds 1 and 2 consist of similar [(NiL)2M(μ1,5-N(CN)2)] (M = Ni for 1 and Cd for 2) angular trinuclear units in which two terminal "metalloligands" [NiL] coordinate to the central nickel(ii) (in 1) or cadmium(ii) (in 2) ion through phenoxido oxygen atoms. The μ1,5-bridging dicyanamido spacers connect the central Ni(ii) or Cd(ii) of one node to terminal Ni(ii) of two different nodes giving rise to 2D CPs. Compound 3 also contains trinuclear units with the same formula as those of 1 and 2: [(NiL)2M(μ1,5-N(CN)2)] (M = Zn in 3). The main differences are that these units are linear in 3 and the dicyanamide spacers link only the nickel atoms of neighbouring nodes. As in 1 and 2, these trinuclear units are connected to four other units via four μ1,5-bridging dicyanamido ligands, giving rise to 2D CP with a similar topology: a uninodal 4-connected underlying net with the sql (Shubnikov tetragonal plane net) topology and (44·62) point symbol. The magnetic properties show the presence of moderate intra-trimer antiferromagnetic interactions in 1 (J = -12.9 cm-1) and weak antiferromagnetic interactions between the terminal Ni(ii) ions in 2 (J = -2.4 cm-1). In 3 the Ni(ii) ions are well isolated by the central Zn(ii) ion and accordingly, only a very weak antiferromagnetic interaction through the single μ1,5-bridging dicyanamido ligands is observed (J = -0.44 cm-1, D = -3.9 cm-1). This journal is

Fe3O4@SiO2@Im[Cl]Mn(III)-complex as a highly efficient magnetically recoverable nanocatalyst for selective oxidation of alcohol to imine and oxime

An efficient and environmentally friendly oxidation process for the one-pot preparation of oxime, imine and carbonyl compounds through alcohol oxidation in the presence of H2O2 and/or O2 have been developed by a melamine-Mn(III) Schiff base complex supported on Fe3O4@SiO2–Cl nanoparticles, named as Fe3O4@SiO2@Im[Cl]Mn(III)-complex nanocomposite, at room temperature. Direct oxidation of alcohol to carboxylic acid was performed using the catalyst in the presence of molecular O2 at room temperature in a different approach. The oxidation products were obtained with excellent yields and high TOFs. The properties of the catalyst were characterized by Fourier transform infrared spectroscopy (FTIR), elemental analysis (C, H, N), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS), energy dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), inductive coupled plasma (ICP), cyclic voltammetry (CV), nuclear magnetic resonance (1H & 13C NMR), vibration sample magnetometer (VSM), Brunauer– Emmett–Teller (BET) and differential pulse voltammetry (DPV) analyses. The mechanism of the oxidation processes was investigated for the both H2O2 and O2 oxidants. The role of the imidazolium moiety in the catalyst as a secondary functionality was investigated. Chemoselectivity behavior of the catalyst was studied by some combinations. The catalyst could be recycled from the reaction mixture by a simple external magnet and reused for several times without any considerable reactivity loss.