2-羟基-1-萘甲醛缩氨基硫脲稀土金属配合物的合成

合成了一种新的Schiff碱配体——2-羟基-1-萘甲醛缩氨基硫脲(LH)及其6种新型稀土金属配合物ML(M=Er,Gd,Nd,Pr,Sm,Tb),其结构经UV,1H MNR和IR表征。实验结果表明,配合物同时含有M-O,M-N和M-S键形成的五元环和六元环各一个,LH为多齿配体。     

Utility of 2-Methoxy-1-naphthaldehyde in Heterocyclic Synthesis

This review describes the synthesis and reactions of 2-methoxy-1-naphthaldehyde as building block and important intermediate for the synthesis of polyfunctionalized heterocyclic compounds with pharmacological interest.     

New Copper（Ⅱ） and Nickel（Ⅱ） Complexes of 4-Morpholinoacetophenone Thiosemicarbazone： Structural, Electrochemical and Antimicrobial Studies

4-Morpholinoacetophenone thiosemicarbazone, MAPT, and its nickel（Ⅱ） and copper（Ⅱ） complexes have been prepared and characterized by elemental analysis, magnetic susceptibility, spectral methods （FT-IR, ^1H NMR） and cyclic voltammetry. Electrochemical behaviors of the complexes have been studied by cyclic voltammetry in DMF media showing metal centered reduction processes for both of them. The redox properties, nature of the electrode processes and the stability of the complexes were discussed. [Cu（MAPT）2]Cl2 complex shows Cu（Ⅱ）/Cu（Ⅰ） couple and quasi-reversible wave associated with the Cu（Ⅲ）/Cu（Ⅱ） process. The reduction/oxidation potential values depend on the structures of complexes. Also, the antimicrobial activities of these complexes were determined against S. aureus, E. coli and B. subtilis.     

Spectrophotometric and First Derivative Spectrophotometric Determination of Magnesium with 1-Hydroxy-2-Carboxyanthraquinone

Abstract

1-Hydroxy-2-carboxyanthraquinone reacts with magnesium in ethanol-water mixtures to form a red complex having an absorption maximum at 490 nm in alkaline medium. A detailed study of the characteristics of this complex has been carried out and a spectrophotometric method for the determination of magnesium at the 0.4–4.0 μg ml^?1 level is proposed. The method has been sensitized by employing first derivative spectrophotometry. By the use of the derivative approach magnesium can be determined between 0.08–0.40 μg ml^?1. Statistical analysis of the results is also described.     

Preparation, Spectral and Thermal Studies of Y(III) and Lanthanide(III) 1-Hydroxy-2-Naphthoates

Complexes of lanthanide(III) (La–Lu) and Y(III) with 1-hydroxy-2-naphthoic acid were obtained as crystalline compounds with a general formula Ln[C₁₀H₆(OH)COO]₃⋅nH₂O:n=6 for La–Tm and Y, n=2 for Yb and n=0 for Lu. IR spectra of the prepared complexes were recorded, and their thermal decomposition in air were investigated. Spectroscopic data suggest that in the coordination of metal-organic ligand only oxygen atoms from the carboxylate group take part. When heated, the complexes decompose to the oxides Ln₂O₃, CeO₂, Pr₆O₁₁ and Tb₄O₇ with intermediate formation of Ln(C₁₁H₇O₃)(C₁₁H₆O₃). This revised version was published online in August 2006 with corrections to the Cover Date.     

Excited-State Double Proton Transfer of 1, 8-Dihydroxy-2-Naphthaldehyde: a MS-CASPT2//CASSCF Study

Excited-state double proton transfer (ESDPT) is a controversial issue which has long been plagued with theoretical and experimental communities. Herein, we took 1, 8-dihydroxy-2-naphthaldehyde (DHNA) as a prototype and used combined complete active space self-consistent field (CASSCF) and multi-state complete active-space second-order perturbation (MS-CASPT2) methods to investigate ESDPT and excited-state deactivation pathways of DHNA. Three different tautomer minima of S1-ENOL, S1-KETO-1, and S1-KETO-2 and two crucial conical intersections of S1S0-KETO-1 and S1S0-KETO-2 in and between the S₀ and S₁ states were obtained. S1-KETO-1 and S1-KETO-2 should take responsibility for experimentally observing dual-emission bands. In addition, two-dimensional potential energy surfaces (2D-PESs) and linear interpolated internal coordinate paths connecting relevant structures were calculated at the MS-CASPT2//CASSCF level and confirmed a stepwise ESDPT mechanism. Specifically, the first proton transfer from S1-ENOL to S1-KETO-1 is barrierless, whereas the second one from S1-KETO-1 to S1-KETO-2 demands a barrier of ca. 6.0 kcal/mol. The linear interpolated internal coordinate path connecting S1-KETO-1 (S1-KETO-2) and S1S0-KETO-1 (S1S0-KETO-2) is uphill with a barrier of ca. 12.0 kcal/mol, which will trap DHNA in the S₁ state while therefore enabling dual-emission bands. On the other hand, the S₁/S₀ conical intersections would also prompt the S₁ system to decay to the S₀ state, which could be to certain extent suppressed by locking the rotation of the C5$-$C8$-$C9$-$O10 dihedral angle. These mechanistic insights are not only helpful for understanding ESDPT but also useful for designing novel molecular materials with excellent photoluminescent performances.     

4-Hydroxy-2-quinolones. 56. 4-(Adamant-1-yl)thiazolyl-2-amides of 1-R-4-Hydroxy-2-oxoquinoline-3-carboxylic Acids as Potential Antitubercular Agents

The synthesis, antitubercular, anti-HIV, and antitumor activity of the 4-(adamant-1-yl)thiazolyl-2-amides of 1-R-4-hydroxy-2-oxoquinoline-3-carboxylic acids have been studied. An efficient method for purifying the 4-hydroxy-2-oxoquinoline derivatives from their metal salts is proposed.     

Potentiometric studies on the complexation equilibria between some trivalent lanthanide metal ions and biologically active 2-hydroxy-1-naphthaldehyde thiosemicarbazone (HNATS)

Summary The chelation behaviour of some trivalent lanthanide and yttrium metal ion with biologically active 2-hydroxy-1-naphthaldehyde thiosemicarbazone (HNATS) has been investigated by potentiomotric measurements at 20±0.5°C in 75% (v/v) dioxane-water medium at various ionic strengths of sodium perchlorate. The method of Bjerrum and Calvin, as modified by Irving and Rossotti has been used to find out the values of (average number of ligand bound per metal ion) andpL (free ligand exponent). The formation constants of metal chelates have been computed on a PC-XT computer, using a program patterned after that of Sullivan et al. to give _n values using weighted least squares method. TheS _min values (S _min =²) have been calculated. The order of formation constants of chelates was found to be: La³⁺3+3+3+3+3+3+3+3+3+. The formation constants of the chelates formed have been correlated to size and ionization potentials of the metal ions.

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Potentiometrische Untersuchungen der Komplexierungsgleichgewichte zwischen einigen trivalenten Metallionen und biologisch aktivem 2-Hydroxy-1-naphthaldehyd-thiosemicarbazon (HNATS)

Zusammenfassung Es wurde das Chelierungsverhalten einiger trivalenter Lanthanidenionen mit biologisch aktivem 2-Hydroxy-1-naphthaldehyd-thiosemicarbazon (HNATS) mittels potentiometrischer Messungen bei 20±0.5°C in 75% (v/v) Dioxan-Wasser bei verschiedener Ionenstärke an Natriumperchlorat untersucht. Die Methode nach Bjerrum und Calvin in der Modifikation nach Irving und Rossotti wurde zur Ermittlung der Werte (mittlere Anzahl an Liganden pro Metallion) undpL (Exponent an freiem Liganden) verwendet. Die Komplexbildungskonstanten wurden in Anlehnung an Sullivan et al. an einem PC-XT Computer errechnet. DieS _min-Werte (S _min=²) wurden ebenfalls bestimmt. Die Reihung der Chelatbildungskonstanten war: La³⁺3+3+3+3+3+3+3+3+3+. Die Bildungskonstanten sind mit der Größe und dem Ionisierungspotential der Metallionen zu korrelieren.

     

Synthesis and spectral characterization of homobimetallic molybdenum(VI) complexes derived from bis(2-hydroxy-1-naphthaldehyde)succinoyldihydrazone

The reaction of bis(2-hydroxy-1-naphthaldehyde)succinoyldihydrazone with bis(acetylacetonato)dioxomolybdenum(VI) (MoO₂(acac)₂) in 1 : 3 molar ratio in EtOH : water mixture (95 : 5) affords a complex of composition [(MoO₂)₂(nsh)(H₂O)₂] · C₂H₅OH. The reaction of [(MoO₂)₂(nsh)(H₂O)₂] · C₂H₅OH with Lewis bases, namely pyridine, 2-picoline, 3-picoline, and 4-picoline, yields [(MoO₂)₂(nsh)(B)₂] · C₂H₅OH (where B = pyridine, 2-picoline, 3-picoline, and 4-picoline). Further, when this complex was reacted with 1,10-phenanthroline and 2,2′-bipyridine in 1 : 3 molar ratio in anhydrous ethanol the binuclear complexes [(μ₂-O)₂(MoO₂)₂(H₄nsh)(phen)] · C₂H₅OH and [(μ₂-O)₂(MoO₂)₂(H₄nsh)(bpy)] · C₂H₅OH were obtained. All of the complexes have been characterized by analytical, magnetic moment, and molar conductivity data. The structures of the complexes have been discussed in the light of electronic, IR, ¹H NMR, and ¹³C NMR spectroscopy.     

Synthesis and characterization of molybdenum(V,VI) complexes derived from bis(2-hydroxy-1-naphthaldehyde)malonoyldihydrazone

Monometallic molybdenum(VI) complexes [MoO₂(CH₂LH₂)]?·?H₂O (1), [Mo₂O₄(CH₂LH₂)₂(A)₂] (A?=?py (2), 2-pic (3), 3-pic (4) and 4-pic (5)) and molybdenum(V) complexes [Mo(CH₂LH₂)(inh)]?·?H₂O (6) and [Mo(CH₂LH₂)(slh)] (7) of bis(2-hydroxy-1-naphthaldehyde)malonoyldihydrazone (CH₂LH₄) have been synthesized and characterized by various physico-chemical and spectroscopic studies. The compositions of the complexes have been established by elemental analyses and molecular weight determination. The structural assessment of the complexes has been done on the basis of data obtained from molar conductances, magnetic moment studies, electronic, infrared, electron paramagnetic resonance (EPR), proton nuclear magnetic resonance, and ¹³C proton nuclear magnetic resonance spectroscopic studies. The molar conductance values for the complexes in DMSO suggest that they are non-electrolytes. The magnetic moment values for 6 and 7 correspond to one unpaired electron while the remaining complexes are diamagnetic. Complexes 1, 6, and 7 have six-coordinate octahedral stereochemistry around molybdenum, while 2–5 are eight-coordinate dodecahedral around the metal centers. EPR spectral features suggest that 7 is less symmetrical than 6.     

Antitumor Comparison of Three α-N-Heterocyclic Thiosemicarbazone Derivatives'Crystal Structures of Bis(2-acetylpyridine)thiocarbonohydrazone and Bis(imidazole-2-carboxaldehyde)thiocarbonohydrazone

T A series of ligands,HL1(2-acetylpyridine thiosemicarbazone),H2L2(bis(2-acetylpyridine)thiocarbonohydrazone)and H2L3(bis(imidazole-2-earboxaldehyde)thiocarbonohydrazone)was synthesized.H2L2 and H2L3 were characterized by elemental analysis,IR spectra and singlecrystal X-ray diffraction studies.Hydrogen bonds link different components to stabilize the crystal structure in the two ligands.To comprehend the structure-activity relationship well,the three ligands are all tested against human K562 leucocythemia cell line with IC50 analysis.Different substituent groups on the ligands show different levels of antitumor activity.By comparison with the other species studied,H2L2 with thiocarbonohydrazone along with 2-acetylpyridine is the most active compound with ICs0=2.48 μM.     

Synthesis,characterization, reactivity,and electrochemical studies of manganese(IV) complexes of bis(2-hydroxy-1-naphthaldehyde)adipoyldihydrazone

Manganese(IV) complexes [Mn^IV(npah)(H₂O)₂] (1) and [Mn^IV(npah)(A)₂]?·?nH₂O (where A?=?py (2), 2-pic (3), 3-pic (4), 4-pic (5)) and Mn^IV(npah)(NN)] (NN?=?bpy (6) and phen (7)) have been synthesized from bis(2-hydroxy-1-naphthaldehyde)adipoyldihydrazone in methanol. The composition of the complexes has been established by elemental analyses. Complex 3 has been characterized by mass spectral data also. Structural assessment of the complexes has been based on data from molar conductance, magnetic moment, electronic, electron paramagnetic resonance, and infrared (IR) spectral studies. Molar conductances of the complexes in DMSO suggest non-electrolytes. Magnetic moment and EPR studies suggest +4 oxidation state for manganese in these complexes. Electronic spectral studies suggest six-coordinate octahedral geometry around the metal ions. IR spectra reveal that H₄npah coordinates to the metal in enol form. Reaction of the complexes with benzyl alcohol and SO₂ has been investigated. Cyclic voltammetric studies of the complexes have also been carried out.     

New Mononuclear and Binuclear Cu(II), Co(II), Ni(II), and Zn(II) Thiosemicarbazone Complexes with Potential Biological Activity: Antimicrobial and Molecular Docking Study

Herein, we report the synthesis of eight new mononuclear and binuclear Co²⁺, Ni²⁺, Cu²⁺, and Zn²⁺ methoxy thiosemicarbazone (MTSC) complexes aiming at obtaining thiosemicarbazone complex with potent biological activity. The structure of the MTSC ligand and its metal complexes was fully characterized by elemental analysis, spectroscopic techniques (NMR, FTIR, UV-Vis), molar conductivity, thermogravimetric analysis (TG), and thermal differential analysis (DrTGA). The spectral and analytical data revealed that the obtained thiosemicarbazone-metal complexes have octahedral geometry around the metal center, except for the Zn²⁺-thiosemicarbazone complexes, which showed a tetrahedral geometry. The antibacterial and antifungal activities of the MTSC ligand and its (Co²⁺, Ni²⁺, Cu²⁺, and Zn²⁺) metal complexes were also investigated. Interestingly, the antibacterial activity of MTSC- metal complexes against examined bacteria was higher than that of the MTSC alone, which indicates that metal complexation improved the antibacterial activity of the parent ligand. Among different metal complexes, the MTSC- mono- and binuclear Cu²⁺ complexes showed significant antibacterial activity against Bacillus subtilis and Proteus vulgaris, better than that of the standard gentamycin drug. The in silico molecular docking study has revealed that the MTSC ligand could be a potential inhibitor for the oxidoreductase protein.     

Synthesis of Some N1-(3-Hydroxy-2-pyridyl)benzamides

Benzoxazoles are of special interest because of having various types of biological properties such as antihistaminic, antihelmintic antifungal and antibacterial activities. ¹ Hisano, T., Ichikawa, M., Tsumoto, K. and Tasaki, M. 1982. Chem. Pharm. Bull, 30: 2996 [CSA][Crossref], [Web of Science ®] , [Google Scholar], ² Prudhomme, M., Guyot, J. and Jeminet, G. 1986. J. Antibiotics, 39: 934 [CSA][Crossref], [PubMed], [Web of Science ®] , [Google Scholar], ³ Ersan, S., Nacak, S., Berkem, R. and Özden, T. 1997. Arzneim. Forsch, 47: 963 [CSA][PubMed], [Web of Science ®] , [Google Scholar], ⁴ Sener, E., Yalc?n, ?., Temeiz, Ö., Ören, ?., Ak?n, A. and Ucartürk, N. 1997. Farmaco, 52: 99 [CSA][PubMed] , [Google Scholar], ⁵ Ören, ?., Temiz, Ö., Yalc?n, ?., Sener, E., Ak?n and Ucartürk, N. 1997. Forsch, 47: 1393 [CSA] [Google Scholar], ⁶ Temiz, Ö., Ören, ?., Sener, E., Yalc?n, ?. and Ucartürk, N. 1998. Farmaco, 53: 337 [CSA][CROSSREF][Crossref], [PubMed] , [Google Scholar], ⁷ Yalc?n, ?., Ören, ?., Sener, E., Ak?n, A. and Ucartürk, N. 1992. J. Med. Chem, 27: 401 [CSA][CROSSREF][Crossref], [Web of Science ®] , [Google Scholar], ⁸ Temiz, Ö., Ören, ?. and Altanlar, N. 2002. Farmaco, 57: 175 [CSA][CROSSREF][Crossref], [PubMed] , [Google Scholar], ⁹ Sener, E., Temeiz, Ö., Yalc?n, ?. and Altanlar, N. 2000. Farmaco, 55: 397 [CSA][CROSSREF][Crossref], [PubMed] , [Google Scholar], ¹⁰ Ören, ?., Temiz, Ö., Yalc?n, ?., Sener, E. and Altanlar, N. 1998. Eur. J. Pharm. Sci., 7: 153 [CSA][Crossref], [Web of Science ®] , [Google Scholar] Benzamide derivatives, as the possible metabolites of benzoxazoles, show various types of biological activities. ¹¹ Sener, E., Bingöl, K., Ören, ?., Arpac?, Ö., Yalc?n, K. ?. and Altanlar, N. 2000. Farmaco, 55: 469 [CSA][CROSSREF][Crossref], [PubMed] , [Google Scholar], ¹² Sener, E., Yalc?n, K. ?. and Altanlar, N. 2002. Farmaco, 57: 451 [CSA][CROSSREF][Crossref], [PubMed] , [Google Scholar] Some N-(2-hydroxyphenyl)- benzamides, which showed significant activity compared to phenylacetamides and furamides,11 have been synthesized by treating 2-aminophenol with carboxylic acid chlorides under weak basic solution. ¹¹ Sener, E., Bingöl, K., Ören, ?., Arpac?, Ö., Yalc?n, K. ?. and Altanlar, N. 2000. Farmaco, 55: 469 [CSA][CROSSREF][Crossref], [PubMed] , [Google Scholar], ¹² Sener, E., Yalc?n, K. ?. and Altanlar, N. 2002. Farmaco, 57: 451 [CSA][CROSSREF][Crossref], [PubMed] , [Google Scholar] However, synthesis and especially biological activity of N-(3-hydroxy-2-pyridyl)benzamides were not studied well. Owing to the versatility of benzamides we have extended the reaction of 2-amino-3-pyridinol with different carboxylic acid chlorides in order to preparation of some new benzamide derivatives containing a hydroxypyridyl ring.     

Stabilities of some bivalent transition metal ions with 2-hydroxy naphthaldehyde semicarbazones and thiosemicarbazones in dioxane-water mixtures: A potentiometric study

Summary Equilibria between 2-hydroxy naphthaldehyde derivatives (semicarbazone and thiosemicarbazone) and proton or some bivalent metal ions have been investigated potentiometrically at a constant ionic strength and different compositions of the mixed solvent (dioxane: water). The method of Bjerrum and Calvin [1, 2], as modified by Irving and Rossotti [3], has been used to determine the values ofn andpL. The stability constants have been calculated following Sullivan et al. [4] to give _n values. The values ofS _min=² have also been calculated. The order of stability constants was found to be found to be UO ₂ ²⁺ > Cu²⁺ > Ni²⁺ > Co²⁺ > Zn²⁺ > Pb²⁺ > Cd²⁺ > Mn²⁺ > Mg²⁺. The effect of varying the dielectric constant of the medium on the stability constants of the complexes has also been investigated at an ionic strength of 0.100M NaClO₄ and a temperature of 20±0.5°C.

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Die Stabilitäten einiger bivalenter Übergangsmetallionen mit 2-Hydroxynaphthaldehyd-Semicarbazonen und -Thiosemicarbazonen in Dioxan-Wasser-Mischungen: Eine potentiometrische Studie

Zusammenfassung Es wurden die Gleichgewichte zwischen 2-Hydroxynaphthaldehyd-Semicarbazonen und -Thiosemicarbazonen einerseits und Proton oder zweiwertigen Übergangsmetallionen andererseits potentiometrisch bei einer konstanten Ionenstärke und verschiedenen Zusammensetzungen von Dioxan und Wasser als gemischtem Lösungsmittel untersucht. Die Methode von Bjerrum und Calvin nach der Modifikation von Irving und Rossotti wurde zur Evaluierung der Werte fürn undpL verwendet. Die Stabilitätskonstanten und _n -Werte wurden nach Sullivan et al. berechnet. Die WerteS _min=² wurden ebenfalls bestimmt. Die Reihenfolge der Stabilitätskonstanten war UO ₂ ²⁺ > Cu²⁺ > Ni²⁺ > Co²⁺ > Zn²⁺ > Pb²⁺ > Cd²⁺ > Mn²⁺ > Mg²⁺. Außerdem wurde der Effekt wechselnder Dielektrizitätskonstanten des Lösungsmittels auf die Stabilitätskonstanten der Komplexe bei einer Ionenstärke von 0.100M NaClO₄ und einer Temperature von 20±0.5°C untersucht.

     

Synthesis,Structural, and Antibacterial Studies of Some Mixed Ligand Complexes of Zn(II), Cd(II), and Hg(II) Derived From Citral Thiosemicarbazone and N-Phthaloyl Amino Acids

A series of new mixed ligand complexes of Zn(II), Cd(II), and Hg(II) with cis-3,7-dimethyl-2,6-octadienthiosemicarbazone (CDOTSC; LH) and N-phthaloyl amino acids (AH) have been synthesized by the reaction of metal dichloride with ligands CDOTSC and N-phthaloyl derivative of DL-glycine (A₁H), L-alanine (A₂H), or L-valine (A₃H) in a 1:1:1 molar ratio in dry refluxing ethanol. All the isolated complexes have the general composition [M(L)(A)]. The plausible structure of these newly synthesized complexes has been proposed on the basis of elemental analyses, molar conductances, molecular weight measurement, and various spectral (IR, ¹H NMR, and ¹³C NMR) studies, and four coordinated geometries have been assigned to these complexes. All the complexes and ligands have been screened for their antibacterial activity.     

Synthesis and Thermodynamic Investigation of 4-Amino-6-Hydroxy-2-Mercapto Pyrimidine (AHMP) Complexes with Some Selected Divalent Metal(II) Ions

The synthesis and characterization of zinc(II), cadmium(II), lead(II), mercury(II) and phenylmercury(II) complexes of 4-amino-6-hydroxy-2-mercapto pyrimidine (AHMP) are reported. The stoichiometry of the complexes was found to be 1:2 except for the phenylmercury(II) complex where the ratio is 1:1. Characterization of these complexes was carried out by means of elemental analyses, IR and ¹H NMR measurements. In these complexes the ligand is bonded to the metal through its sulfur atom. The potentiometric results showed the formation of 1:1 and 1:2 complexes and the corresponding stability constants were determined for both Zn(II) and Cd(II) ions. The high insolubility of mercury(II), phenylmercury(II) and lead(II) complexes prevented the determination of their stability constants. The concentration distribution of the complexes in solution was evaluated. The effect of temperature on the dissociation constant of AHMP and the formation constants of both the Zn-AHMP and Cd-AHMP complexes were studied and the thermodynamic parameters were calculated.     

Synthesis and Characterization of Zinc(II) Complexes with 3,4-Dimethoxybenzaldehyde Thiosemicarbazone: The Crystal Structure of [Zn(34-MBTSC)2Cl2]

Abstract

The synthesis and characterization of three zinc(II) complexes [Zn(34-MBTSC)₂Cl₂] (1), [Zn(34-MBTSC)₂Br₂] (2), and [Zn(34-MBTSC)₂I₂] (3) of 3,4-dimethoxybenzaldehyde thiosemicarbazone (34-MBTSC) are reported. Elemental analysis (CHN) and spectral (FT-IR and ¹H-NMR) measurements have been used to characterize the complexes. In addition, the structure of the complex 1 has been determined by X-ray diffraction methods. In these complexes, the zinc(II) ion is bonded to two thioketonic sulfur donors in η¹-S bonding mode and to two halide ions in tetrahedral geometry.

Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional figures.     

Synthesis,Spectroscopic Studies,and Biological Activity of Organosilicon(iv) Complexes of Ligands Derived from 2-Aminobenzothiazole Derivatives and 2-Hydroxy-3-Methoxy Benzaldehyde

Abstract

The Schiff bases derived from the condensation of 2-aminobenzothiazole derivatives and 2-hydroxy-3-methoxybenzaldehyde and their silicon(IV) complexes with the general formula R₂Si(L)Cl (R = Et, Bu, Ph, L = 2-(2-hydroxy-3-methoxy) benzylideneaminobenzo-thiazole) have been synthesized. These complexes have been characterized by elemental analysis, molar conductance, and spectroscopic studies including IR and NMR (¹H, ¹³C, and ²⁹Si) spectroscopy. The analytical data suggest trigonal bipyramidal geometry around the silicon atom in the resulting complexes. The ligands and their organosilicon complexes have also been evaluated for in vitro antimicrobial activity against bacteria (Staphylococcus aureus, Bacillus subtilis, and Escherichia coli) and fungi (Aspergillus niger and Candida albicans). The complexes were found to be more potent as compared to the ligands.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.