Microsoft Word - 73-87 Chemistry | 73 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 New Bis(dithiocarbamate) Ligand for Complex Formation; Synthesis, Spectral Analysis and Bacterial Activity Enaam I. Yousif Hasan A. Hasan Dept. of Chemistry/College of Education for Pure Science (Ibn Al-Haitham)/ University of Baghdad Received in: 21/February/2016,Accepted in:5/April/2016 Abstract A range of macrocyclic dinuclear metal (II) dithiocarbamate-based complexes are reported. The preparation of complexes was accomplished from either mixing of the prepared ligand with a metal ion or through a template one-pot reaction. The preparation of the bis- amine precursor was achieved through several synthetic steps. The free ligand; potassium 2,2'-(biphenyl-4,4'-diylbis(azanediyl))bis(1-chloro-2-oxoethane-2,1- diyl)bis(cyclohexylcarbamodithioate) (L) was yielded from the addition of CS2 to a bis-amine precursor in KOH medium.A variety of analytical and physical methods were implemented to characterise ligand and its complexes. The analyses were based on spectroscopic techniques (FTIR, UV-Vis, mass spectroscopy and 1H, 13C-NMR spectroscopy), melting points, elemental analysis, thermal properties, magnetic susceptibility and conductance. The analytical and physical techniques confirmed the formation of macrocyclic complexes of the general formulae [M(L)]2 (M= Mn II, CoII, NiII, CuII, ZnII and CdII). The proposed structure around MnII, CoII, ZnII and CdII is a tetrahedral, while NiII and CuII complexes adopt square planar geometries. The prepared compounds were screened against four bacterial species (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus stubtilis). The anti-bacterial test indicated that the complexes are more active against these bacterial strains, compared with the free ligand. Keywords: Bis(dithiocarbamate) ligand; Metal complexes; Spectral studies; Thermal properties; Bacterial activity. Chemistry | 74 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 1. Introduction Dithiocarbamates are flexible compounds that have shown a range of applications. These species played a significant role in the expansion of chemistry, due to their importance in synthetic inorganic [1], bioinorganic [2], analytical [3] and environmental chemistry [4]. Dithiocarbamates (DTCs) are flexible ligands that have the ability to bind transition and representative elements. The importance of dithiocarbamates (DTCs) is due to their capability to stabilize metal ion in a variety of oxidation states. This is related to their strongly chelating ability towards metal ions. Further, upon complexation, these species permitting the metal ion to adopt its most preferable geometry [5]. The presence of the anionic CS2¯ moiety allowed DTCs molecules to achieve a range of binding modes; monodentate, bidentate or bridging, upon complexation [6-8]. Dithiocarbamates are essential materials that have been widely explored due to their applications in coordination chemistry [1], materials science [9], medicine and radiopharmaceutical chemistry [10, 11], sensing technology [12] and in the industry [13]. More, the act of dithiocarbamates against some tumours, fungi, bacteria, and other microorganisms [14, 15] make them a hot topic for several research groups. In this paper, we report the preparation, spectral analysis and bacterial activity of a new DTC ligand and its macrocyclic metal-based complexes. 2. Experimental 2.1. Chemicals Chemicals and solvents were purchased commercially and used as received. 2.2. Instruments Elemental micro-analyses (C, H, N and S) for ligand and its metal complexes were conducted on a Euro EA 3000. Electrothermal Stuart SMP40 apparatus was used to record melting points. FT-Infrared spectra were recorded as KBr discs with a Shimadzu 8300s FT-IR spectrophotometer in the range 4000-400 cm-1 and as CsI discs in the range 400-200 cm-1. UV-Vis spectra were obtained with 10-3 M solutions between 200-1100 nm in dimethylsulfoxide (DMSO) spectroscopic grade solvent at 25 °C using a Perkin-Elmer spectrophotometer Lambda. Thermogravimetric analysis was carried out using a STA PT- 1000 Linseis company /Germany. Electrospray mass spectroscopy technique (ESMS) was used to measure mass spectra for samples. NMR spectra (1H, 13C-NMR) were acquired in DMSO-d6 solutions using a Brucker-300 for 1H-NMR and 75 MHz for 13C-NMR, respectively with tetramethylsilane (TMS) for 1H NMR. A Shimadzu (A.A) 680 G atomic absorption spectrophotometer was implemented to determine metal content in complexes. Conductivity measurements were performed using a Jenway 4071 digital conductivity meter with DMSO solutions at room temperature. A magnetic susceptibility balance (Sherwood Scientific) was used to determine magnetic moments of complexes. 3. Synthesis 3.1. Preparation of the bis-amine precursors In this work, standard methods reported in [16, 17] were used for the preparation of the precursors. The free bis-amine precursor was prepared by two steps, and as follows: 3.1.1. Preparation of N,N'-(biphenyl-4,4'-diyl)bis(2-dichloroacetamide) To a mixture of benzidine (2.44g, 13.24mmol) dissolved in chloroform (75mL), was added with stirring potassium hydroxide (2.626g, 46.88mmol) in water (35mL). To this mixture, dichloroacetyl chloride (6.90g, 46.88mmol) in chloroform (75mL) was added drop- wise with stirring. The mixture was left to stir for 15 minutes, during which time a white Chemistry | 75 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 precipitate was formed, which filtered off and then washed with diethyl ether (30mL). The collected white solid was air-dried, m.p=235-237 ºC. Yield: 9.04g, (94%). FTIR (cm-1), 3249 ν(-CON-H), 1674 ν(C=O), 1606 δ(N-H), 1529 νar(C=C). The electrospray (+) mass spectrum of the N,N'-(biphenyl-4,4'-diyl)bis(2-dichloroacetamide) exhibited the parent ion peak at m/z = 406.1(M)+ (28%) for C16H12Cl4N2O2; requires =406.09 and the following fragments; 280.2 (40%) and 154.2 (13%) correspond to [M-(NH-CO-CHCl2)] + and [M-(NH-CO-CHCl2)+(NH- CO-CHCl2)] +, respectively. NMR data (ppm), δH(300 MHz, DMSO-d6): 8.63 (2H, s, N-H), 7.68, 7.69 (4H, d, JHH= 2.1 Hz), 7.40, 7.41 (4H, d, JHH= 2.4 Hz) (C4, 4`, 6, 6`-H) (C5, 5`, 7, 7`- H)Ar-H, 6.70 (2H, s,CHCl2) (C1, 1`-H); δC(75MHz, DMSO-d6): 59.90 (CHCl2, 2C1), 120.26 and 126.81 (Ar-C4, 5 ,6, 7), 161.32 (2C2=O). 3.1.2. Preparation of bis-amine N,N'-(biphenyl-4,4'-diyl)bis(2- (cyclohexylamine) chloroacetamide) An excess of cyclohexylamine (3.90g, 39.40mmol) was warmed up to 40 ºC, and then N,N'-(biphenyl-4,4'-diyl)bis(2-dichloroacetamide) (4.00g, 9.85mmol) was added portion-wise with stirring. The reactants was stirred at 40 ºC for 12 h, and then water (200mL) was poured in the mixture. The title compound was extracted into dichloromethane (4 x 50 mL), washed with water (200mL) and dried over K2CO3. On removing solvent under reduced pressure, brown oil compound was collected as the required material. Yield: 2.86g (54 %). FTIR cm- 1, 3342 ν(N-H), 3222 ν(-CON-H), 3032 νar(C-H), 2929 and 2858 νali(C-H), 1676 ν(C=O), 1622 δ(N-H), 1498 νar(C=C) , 700 ν (C-Cl). The electrospray (+) mass spectrum of the bis- amine showed the parent ion peak at m/z =532.2 (M+H)+ (7%) for C28H34Cl2N4O2, requires =531.52 and the following fragments at m/z =343.9 (16%) , 260.8 (90%) and 154.3 (14%), corresponding to [M-(C6H6-NH-Cl-CO-NH)] +, [M-(C6H6-NH-Cl-CO-NH)+(C6H6)] + and [M- (C6H6-NH-Cl-CO-NH)+(C6H6)+(NH2-Cl-CO-NH)] +, respectively. NMR data (ppm), δH(300 MHz, DMSO-d6): 1.09-1.25 (8H, q, JHH=4.8Hz,(CB, B` F, F`-H)), 1.48-1.52 (12H, m, (CC, C`, D, D`, E, E`-H)), 3.16-3.17 (2H, m, (CA, A`-H)), 3.91 (2H, t, NH), 5.38 (2H, d, JHH=2.1Hz, (C1, 1`- H)), 8.87 (2H, s, amidic-H), 7.59 (4H, d, JHH=6.3Hz, (C4, 4`,6, 6`-H)), 7.54 (4H, d, JHH=6.8Hz, (C5, 5`, 7, 7`-H)) (Aromatic-H); δC (75 MHz, DMSO-d6): 23.90 (CB, B` F, F`-H), 25.16 (CC, C`, E, E`-H), 31.97 (CD, D`), 56.30 (CA, A`), 79.18 (C1, 1`), 119.65 (C4, 4`, 6, 6`), 131.31 (C5, 5`, 7, 7`), 163.64 (C=O, (C2, 2`)). 3.2. Synthesis of free ligand A conventional procedure that used in the preparation of dithiocarbamte compounds [18] was adopted to obtain ligand and as follows: 3.2.potassium2,2'-(biphenyl-4,4'-diylbis(azanediyl))bis(1-chloro-2- oxoethane-2,1-diyl)bis (cyclohexylcarbamodithioate) An excess of KOH (0.126g, 2.25mmol, 4eq) dissolved in H2O (2mL) was added with stirring to a solution of N, N'-(biphenyl-4,4'-diyl)bis(2-(cyclohexylamine)chloroacetamide) (0.30g, 0.56mmol) in 10 mL of a mixture of acetonitrile:water (9:1). The mixture was placed in an ice bath, and then a mixture of CS2 (0.128g, 1.69mmol, 3eq) was added portion-wise with stirring. The mixture was kept at 0 °C for 2 h, and then potassium dithiocarbamate salt was collected as a light yellow solid in good yield (0.28g, 66%), m. p=188-190 ºC. FTIR cm- 1, 3299 ν(-CON-H), 3086 νar(C-H), 1676 ν(C=O), 1622 δ(N-H) 1545, νar(C=C) , 1441ν(N- CS2), 1084, 976 νas, s (CS2) 654ν (C-Cl). The electrospray (+) mass spectrum of the L showed the parent ion peak at m/z=760.4 (M+H)+ (14%) for C30H34Cl2K2N4O2S4; requires =759.98 and the following fragments at m/z=681.6(12%), 529.7(8%), 341.5(55%) and 153.8 (7%) corresponding to [M-(K)2] +, [M-(K)2+(CS2)2] +, [M-(K)2+(CS2)2+(NH-CO-CHCl-N-C6H11)] + and [M-(K)2+(CS2)2+(NH-CO-CHCl-N-C6H11)+(NH-CO-CHCl-N-C6H11)] +. NMR data Chemistry | 76 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 (ppm), δH(300 MHz, DMSO-d6): 1.79-1.83 (2H, m, CA, A`-H), 1.50-1.60 (8H, q, JHH=3 Hz, CB, B` F, F`-H), 1.13-1.19 (12H, m, CC, C`, D, D`, E, E`-H), 5.01-5.02 (2H, s, (C2, 2`-H)) 7.81-7.82 (4H, d, JHH=2.1 Hz, C4, 4`, 6, 6`-H), 7.13-7.14 (4H, d, JHH=2.7 Hz, (C5, 5`, 7, 7`-H) )(Ar-H), 8.50 (2H, s, amidic-H); δC (75 MHz, DMSO-d6): 24.457 (C C, C` E, E`), 25.17 (CD, D`), 32.32 (CB, B`,F, F`), 77.84 (C2, 2`), 119.95 (C4, 4`, 6, 6`), 128.76 (C5, 5`, 7, 7`), 160.33 (C=O) (C3, 3`), 189.87 (C=S) (C1, 1`). 3.3. General procedure for preparation of macrocyclic complexes A standard method that reported in [19, 20] were implemented to prepare the binuclear macrocyclic dithiocarbamate-based complexes, which based on two approaches; (i) from the mixing of the free ligand with a metal ion, and (ii) through a one-pot template reaction. 3.3.1 .Formation of macrocyclic complexes from free ligand The reaction of 1 equivalent of potassium dithiocarbamate salt, dissolved in 20mL of MeCN/H2O (9:1) with 1 equivalent of the metal salt; Mn II, CoII, NiII, CuII, ZnII and CdII, resulted in the formation of the title complex. The reaction mixture was allowed to stir overnight, and deionised H2O was added, if necessary, to precipitate the compound. The solid was collected by filtration, washed with MeOH to give the macrocyclic complex. Elemental micro-analysis, colours and yields for the complexes are presented in (Table1). The 1H-NMR data (ppm) for [Cd(L)]2 complex, δH(300 MHz, DMSO-d6): 1.83-1.84 (2H, m, CA, A` -H), 1.58 (8H, t, JHH=16.1 Hz, CB, B`, F, F`-H), 1.10-1.16 (12H, m, CC, C`-D, D`-E, E`-H), 4.09 (2H, s, C2, 2`- H), 7.70-7.72 (4H, d, JHH=8.1Hz, C C4, 4`6, 6`-H), 6.87-6.91 (4H, d, JHH=12.3 Hz, C5, 5`, 7, 7`- H), 8.19 (2H, s, NH). The 13C-NMR spectrum for the [Cd(L)]2, δC(75 MHz, DMSO-d6): 25.23 (CB, B` F, F`), 25.63 (CD, D`), 32.14 (CC, C`, E, E`), 76.99(C2, 2`), 118.996 (C4, 4`, 6, 6`), 127.87 (C5, 5`, 7, 7`), 159.971 (C=O) (C3, 3`), 208.12 (C =S) (C1, 1`). 3.3.2. Formation of macrocyclic complexes through a one-pot template reaction An excess of KOH (3eq) was added with stirring to a mixture of the secondary amine in acetonitrile/water medium (9:1). To the above solution, carbon disulfide (2.8 equivalents) was added slowly and the mixture was allowed to stir for 10 minutes during which time potassium dithiocarbamate salt was formed. The complex was synthesised in situ (ligand salt was not isolated) by the addition of one equivalent of the metal ion. The obtained mixture was stirred overnight, H2O was poured for precipitation if required. Solid was collected by filtration and allowed to dry in air to yield the macrocyclic complex. Analytical data are similar to that complexes obtained from the free ligand approach. 4. Results and discussion 4.1. Chemistry The addition of carbon disulfide to a secondary bis-amine in the presence of KOH resulted in the formation of the free ligand, see Scheme (1). The ligand was characterised by elemental analysis (Table 1), FTIR (Table 2), UV–Vis (Table 3), mass and 1H, 13C NMR spectroscopy. The formation of dithiocarbamate-based macrocyclic complexes were obtained either via a one-pot approach or from the addition of a metal ion to the free ligand. In the later, the method was based on heating 1 equivalent of the ligand with 1 equivalent of metal chloride, using a mixture of MeCN/H2O as a solvent, see Scheme (2). The objective of this work is to achieve the formation of macrocyclic complexes, in which the metal ion plays a key role in the self-assembly. Complexes, that are stable in air, are not soluble in the common organic solvents. However, they are soluble in hot DMSO. Spectroscopic analyses were used to predict geometries about metal centres. The analytical data (Table 1) support well the Chemistry | 77 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 suggested formulae. The important FT-IR bands of the ligand and its complexes together with their assignments are tabulated in (Table 2). The electronic spectra for the ligand and its complexes are collected in (Table 3). RNH2 O NH O HN NH HN R R - - - - - -- - Cl O Cl NH O Cl HN Cl Cl - - - - - - - - CHCl3 KOH, CS2 Cl D K O Cl Cl Cl C Cl 2+ B F A O NH O HN S S S S N N R R - -- - - - - - - H2N NH2 Cl K stirring Where : R stirring at 0 °C for 2 h 2 3 4 6 5 7 8 8 7 5 4 6 3 2 1 2 3 4 6 5 7 8 8 5 7 4 6 3 2 1 1 2 3 4 5 7 6 8 9 9 6 8 5 7 4 3 2 1 1 1 Cyclohexyl E Scheme (1) Chemistry | 78 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 O NH O HN N H HN R R KOH, CS2 O H N S SN R O HN S SN R O NH S S N R O N H S S N R M M K O H , C S 2 , M C l 2 1 K O NH O HN SS S S N N R R 2 M C l2 K Where: R = Cyclohxyl stirring at 0 °C for 2 h S tirring for 18h M = MnII, CoII, NiII, CuII, ZnII and CdII = L St ir ri ng f or 1 8h Cl Cl Cl Cl Cl Cl Cl Cl Scheme (2) Chemistry | 79 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 4.2. FTIR and NMR spectra The FTIR spectral data is collected in Table (2). FTIR spectrum of L exhibits band at 3299cm-1 due to ν(N–H) stretching. Band related to ν(C=O) amide is observed at 1676 cm-1. Bands assigned to νas(CS2) and νs(CS2) functional groups were observed at 1084, 976 cm -1, while peak related to ν(C-Cl) was detected at 654 cm-1. Evidence for the formation of dinuclear-macrocyclic complexes was deduced from their FTIR spectra. Bands at 1424-1498 cm-1 that resulted from the stretching of the C-N-S bond indicated a partial delocalization of π-electron density within the dithiocarbamate moieties [21]. Peaks detected at 1084-1151 cm-1 and 933-984cm-1 were assigned to νas(CS2) and νs(CS2), respectively indicating an anisobidentate chelation approach of the ligand to the metal atoms [22, 23]. Complexes exhibited two sets of bands around 374-389cm-1, which attributed to ν(M-S) vibration mode, and supporting the asymmetrical chelation mode of the ligand [9]. The 1H and 13C NMR spectra of the ligand exhibited signals related to the various protons and carbon nucleus indicating the formation of the ligand (See Experimental section). The 1H NMR spectrum in DMSO-d6 solution of the ligand  shows peak at ca. 5.00 ppm assigned to CH (C2, 2`-H). The downfield appearance of this signal may be due to attachment to withdrawing groups (C=O, N-H and Cl). The (N-H) peak for the amide moiety appears as expected around 8.50 ppm. The 13C NMR spectrum in DMSO-d6 solution of L shows a chemical shift of the carbonyl moiety at δ= 160.33. The preparation of the free ligand was confirmed by detecting resonance around δ=189.87 ppm, which assigned to quaternary carbon in dithiocarbamate moiety C=S. The 1H- NMR spectrum for [Cd(L)]2 in DMSO-d6 solution displays the (N-H) signal for the amide moiety at δ= 8.19 ppm, confirming the non-involvement of the amide group upon complexation [24]. The 13C NMR spectrum of [Cd(L)]2 exhibits a number of different carbons in a molecule with the appropriate shifting to that observed in the free ligand, indicating the formation of the Cd-complex. The chemical shift for C=S moiety is detected at 208.12 ppm in [Cd(L)]2, compared with that at 189.87 in the free ligand confirming the involvement of this moiety in complexation [25] ( see Figure (1)). 4.3. Mass spectrum The electrospray (+) mass spectrum of [Zn(L)]2 complex. Reveals that the parent ion peak is not observed upon fragmentation. For C60H68Cl4N8O4S8Zn2, requires1494.39. Peaks detected at m/z=1307.3 (9%), 1062.8 (9 %) 748.2 (19 %), 560.8 (8 %) and 245.3 (10 %) related to [M-(NH-CO-CHCl-(N-C6H11))] +, [M-(NH-CO-CHCl-(N-C6H11))+((Ph)2NH-CO- CHCl)]+, [M-(NH-CO-CHCl-(N-C6H11))+((Ph)2NH-CO-CHCl)+((N-C6H11)(CS2)2Zn)] +, [M- (NH-CO-CHCl-(N-C6H11))+((Ph)2NH-CO-CHCl)((N-C6H11)+(CS2)2Zn)+(NH-CO-CHCl-(N- C6H11))] + and [M-(NH-CO-CHCl-(N-C6H11))+((Ph)2NH-CO-CHCl)+((N- C6H11)+(CS2)2Zn)+(NH-CO-CHCl-(N-C6H11) +((N-C6H11)+(CS2)2Zn)] +. 4.4. UV-Vis Spectral data and magnetic susceptibility for the complexes The electronic spectrum of L in DMSO solution revealed peaks at 268 and 359 nm assigned to π → π* and n → π* transitions, respectively [26-28]. The electronic spectra of the complexes exhibited bands at 265-268 nm associated to the ligand field π → π* and n → π* transitions. Bands at 321-343 nm attributed to the charge transfer transitions (CT) in L complexes [29]. The spectrum of the Mn(II)-complex showed a peak at 435 nm related to 6A1 → 4A1 transition, indicating tetrahedral geometry about Mn(II) ion [30, 31]. The magnetic moment value 5.76 B.M of [MnII(L)]2 is typical for a high spin Mn(II) ion, which related to tetrahedral structures for Mn(II)-complexes [30, 32]. The Co(II) complex exhibits an additional peak at 670 nm correlated to 4A2 (F) → 4T1 (p) transition, indicating tetrahedral structure around Co ion [31-32]. The eff value of 4.87 B.M for Co-complex indicates a four- coordinate complex with a tetrahedral arrangement about metal centre [30, 32]. The spectrum Chemistry | 80 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 of the Ni(II)-complex displayed peaks in the forbidden region at 478 and 645 nm attributed to 1A1g (F) → 1B1g (F) and 1A1g (F)→ 1A2g (F), respectively confirming square planar structure around Ni atom [31, 32]. The magnetic moment measurement for [NiII(L)]2 complex reveals a diamagnetic arrangement. The experimental magnetic value of Ni(II) complex along with other analytical data indicated square planar geometry about Ni ion. The spectrum of the Cu(II)-complex exhibited peaks in the d-d region at 721 and 835 nm related to 2B1g→ 2B2g and 2B1g→ 2A2g transitions, respectively indicating square planar geometry around Cu ion [29-31]. The magnetic moment value of 1.64 B.M for [CuII(L)]2 complex confirms the square planar geometry around Cu(II) ion [30, 31]. The electronic spectra of the [Zn(L)]2 and [Cd(L)]2 complexes exhibited peaks at 267, 267 and 339, 330 nm that assigned to the ligand field and charge transfer transitions in Zn- and Cd-complex, respectively [28, 29]. The electronic data, molar conductance and magnetic moment measurements of L complexes with their assignments are listed in (Table 3). 4.5. Thermal analysis Thermal properties of the ligand and some metal complexes are summarised in Table (4). The TG-DSC curves of the ligand and their complexes were measured from ambient temperature up to 600 °C in the atmosphere of nitrogen. The analysis of thermal data showed ligand L is stable up to 85 °C with a weight loss of 15.87%, which attributed to (KCS2) fragment.The peak detected at 128-238ºC related to the (diphenyl- NCOCHClNphenyl+C+CS2) segment with 63.85% weight loss. The third step occurs at 240- 590ºC is related to the loss of (C2H2) fragments with a weight loss of 3.50%. This peak accompanied by an endothermic behaviour in the DSC curve at 574.4 °C. The final residue of the compound is related to the (phenyl-CHOCl) with 12.26% weight loss. Thermal data of Mn(L)]2, [Co(L)]2, [Ni(L)]2 complexes consists of two steps. The weight loss and other thermal properties including lost fragments of the complexes are listed in Table (4), [35, 36]. 4.6. Bacterial activity Dithiocarbamate ligand and its metal complexes were tested for their antimicrobial activity towards four bacterial species (Escherichia coli, Pseudomonas aeruginosa (G−), Staphylococcus aureus and Bacillus stubtilis (G+)). The involvement of DMSO in the biological activity was clarified by separate studies carried out with the solutions of DMSO alone, which showed no activity against any bacterial strains [37]. The measured zones of inhibition against the growing of different microorganisms are tabulated in Table (5). Biological data showed that complexes become potentially more active against these tested bacteria (except [Zn(L)]2 with E. coli and, P. aeruginosa) compared with the free ligand. This may be explained by chelation effect in which the partially sharing of the positive charge of the metal in complexes by the donor atoms present in the ligand and there may be π-electron delocalization through the whole chelate ring that enhances the lipophilic character of the metal chelate structure. This will favour its spread through the lipid of the cell membranes [38, 39]. 5. Conclusion The work is based on the formation of new bimetallic macrocyclic dithiocarbamate complexes. The synthesis of these complexes was accomplished by adopting two routes; (i) from the mixing of the free ligand with a metal ion, or (ii) through a one-pot template reaction. In these complexes, the metal ion plays a key role in the self-assembly. The nature of bonding and proposed structures of the complexes were established by analytical and spectroscopic techniques. These results indicated the isolation of four-coordinate complexes. 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Vol. 30 (1) 2017 Table (1) Colours, yields, melting points and (C, H, N, S) analysis, values for ligand and bis(dithiocarbamate)-based complexes Found (Calca%) Yield (%) m.p. ºC Colour Molecular formula Metal ion 9.11 (9.33) 16.26 (16.88) 7.82 (7.37) 4.21 (4.51) 46.56 (47.41) - 66.00 188 - 190 Light yellow C30H34Cl2K2N4O2S4 L 9.55 (9.62) - 9.05 (9.58) - - 8.25 (8.93) 17. 18 (17.41) - 17.21 (17.32) - - 16.09 (16.15) 7.95 (7.60) - 7.85 (7.57) - - 7.85 (7.25 4.33 (4.65) - 4.07 (4.63) - - 4.07 (4.63) 48.08 (48.91) - 48.15 (48.66) - - 45.11 (45.37) 7.22 (7.46) - 7.42 (7.93) - - 13.82 (14.15) 42.85 50 46.15 41.02 44.87 44.57 242 255 286 278 256 263 Brown Dark green Green Brown Pale yellow Pale yellow C60H68Cl4N8O4S8Mn2 C60H68Cl4N8O4S8Co2 C60H68Cl4N8O4S8Ni2 C60H68Cl4N8O4S8Cu2 C60H68Cl4N8O4S8Zn2 C60H68Cl4N8O4S8Cd2 [Mn(L)]2 [Co(L)]2 [Ni(L)]2 [Cu(L)]2 [Zn(L)]2 [Cd(L)]2 Table (2) FTIR spectral data (wave number) cm-1 of ligand and their complexes. ν (C- N νas(CS2) ν,s(CS2) ν (C- Cl ν(N- CS2) νar(C=C) δ(N-H) ν (C=O) νali(C-H) ν (CH-Cl) νar(C-H) ν (N-H) Comp. 1223 1084 ,976 654 1441 1545 1622 1676 2922, 2844 3086 3299 L 12551151, 980 768 1498 1550 1628 1682 2933, 2850 3095 3293 [Mn(L)]2 12551090 ,980 798 1488 1494 1514 1650 2939, 2850 3010 3249 [Co(L)]2 12651070 ,984 667 1424 1446 1512 1656 2931, 2848 3012 3224 [Ni(L)]2 12401105 ,933 752 1452 1520 1576 1644 2927, 2856 3005 3265 [Cu(L)]2 12281078 ,976 773 1498 1550 1612 1685 2927, 2850 3010 3290 [Zn(L)]2 12281084 ,980 773 1452 1498 1550 1628 2922, 2856 3010 3296 [Cd(L)]2 *= ν (Ni-S) observed at 389.59 and 374.16 cm-1. *= ν (Cd-S) observed at 385.74 cm-1. Chemistry | 85 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 Table (3) UV-Vis spectral data of ligand and bis(dithiocarbamate)-based complexes in DMSO solutions, molar conductance and magnetic moment. Table (4) TGA/DTG/DSC data for ligand and complexes DTG peak temp. °C  Nature of DSC peak and temp. °C  Nature of transformation/interme diate formed% mass found (calc.), mg fragments Decomposition temperature initial-final °C  Stage Stable up to °C   Comp   -   85 Exo   2.3807 (2.2745)(KCS2)85-125 1 85 L  -132.2,173.3 ,215.0,404. 7,483.8 Endo   9.5780 (9.4936)(diphenyl- NCOCHClNphenyl+C+CS2)  128-238 2  -   574.4 Endo   0.5254 (0.5139)(C2H2)   240-590 3  -   120,185 Exo   5.1091 (5.0773)   (2CH2 CH2 CH2 CH2 CH2CHNCHCl HN+ HNCOCHClNCHCH2CH2 CH2 +4CS2 +CHCONH)   110-264   1 110 [Mn(L)]2   -   241, 400.6 Endo  0.4753 (0.4288)   (Cl+CONH) 265-5982  200   185.8 Endo   4.2179 (4.2117)   (HNCOCHClNCHCH2CH2CH2 CH2CH2+4CS2+CH2CH2CH2C H2CH2CHNCH2 CO +CHCOHN)   105-218   1 105 [Co(L)]2   -   455 Endo   2.0267 (2.0039)   (diphenyl-NHCONCHCl + CH2CH2CH2CH2CH2CH2)   220-560   2  µeff (B.M) ΛM(Ω - 1cm2mol-1) Assignment Extinction coefficient ɛmax (dm 3 mol -1 cm -1 ) Wave number (cm-1) Band Positio n λnm Comp. - - Intra-ligand π → π* n → π* 1239 2247 1280 37313 41322 27855 268 342 359 L 5.76 19.9 Intra-ligand π → π* C.T 6A1  4T1 884 393 77 37458 30864 23148 267 324 435 [Mn(L)]2 4.87 8.47 Intra-ligand π → π* C.T 4A2 (F) →4T1 (p) 1028 1613 44 37313 30487 14925 268 328 670 [Co(L)]2 Diamagnetic 5.86 Intra-ligand π → π* C.T 1A1g (F) → 1B1g (F) 1A1g (F)→ 1A2g (F) 1223 2501 455 187 37735 29154 20920 15503 265 343 478 645 [Ni(L)]2 1.64 9.77 Intra-ligand π → π*, C.T 2B1g→ 2B2g 2B1g→ 2A2g 740 669 18 16 37593 31152 13869 11976 266 321 721 835 [Cu(L)]2 Diamagnetic 3.72 Intra-ligand π → π*, n→π* C.T 1226 2419 37458 29498 267 339 [Zn(L)]2 Diamagnetic 2.09 Intra-ligand π → π*, n→π* C.T 976 1795 37458 30303 267 330 [Cd(L)]2 Chemistry | 86 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 Table (5) Bacterial activity of ligand and bisdithiocarbamate-based complexes No. Sample Average inhibition zone (mm) E. coli P. aeruginosa B. sabtuius S. aureus 1 L 6 5 5 3 2 [Mn(L)]2 12 11 13 15 3 [Co(L)]2 13 12 16 15 4 [Ni(L)]2 12 13 12 12 5 [Cu(L)]2 10 12 9 10 6 [Zn(L)]2 - - 13 11 7 [Cd(L)]2 12 17 25 16 Figure (1) 13C NMR spectra in DMSO-d6 solutions for: A) L; B) [Cd(L)]2 Chemistry | 87 2017عام ) 1(العدد 30مجلة إبن الھيثم للعلوم الصرفة والتطبيقية المجلد Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 30 (1) 2017 تحضير وتشخيص ،ليكاند جديد ثنائي داي ثايو كارباميت في تكوين المعقدات طيفي والفعالية البكتيرية انعام اسماعيل يوسف حسن احمد حسن جامعة بغداد) / الھيثم ابن(كلية التربية للعلوم الصرفة / قسم الكيمياء 2016/نيسان/5:بل فيق ،2016/شباط/21:استلم في الخالصة الليكاند بمفاعلة الفلز حضر تضمن البحث تحضير وتشخيص ليكاند ثنائي الثايوكارباميت ومعقداته الحلقية ثنائية وسطا سيتونايتريلمزيج من الماء واال عمالدروكسيد البوتاسيوم باستاالمين الثانوي مع الكاربون ثنائي الكبريت وبوجود ھي . الحر اللكاندعلى لنحصلللتفاعل ةللمواد المتفاعل ةالحر و الثانية طريقة االضافة الواحد الليكانداالولى طريقة تينطريق عمالالمعقدات باست حضرت مع مكافئ من ملح لليكاندالحر من تفاعل مكافئ من ملح البوتاسيوم الليكاندحضر المعقد في طريقة . في دورق التفاعل حيث يتم تحضير المعقد من خالل مزج ثنائي االمين الثانوي مع ةالثانية فھي طريقة االضافة الواحد الطريقة اام, الفلز وسطا سيتونايتريلمزيج من الماء واال عمالباستالكاربون ثنائي الكبريت و ملح الفلز و بوجود ھيدروكسيد البوتاسيوم التحليل الدقيق للعناصر وتقنية اطياف االشعة تحت ةوالمعقدات بوساطشخص الليكاند .المعقدات على لنحصلللتفاعل وقياس درجة االنصھار الموالرية التوصليةو ةالمغناطيسي ةوالحساسي ةوالمرئي ةفوق البنفسجي ةالحمراء واطياف االشع :واطياف الرنين المغناطيسي ةوتقنية طيف الكتل 1H, 13C - NMR spectroscopy. .وكانت المعقدات اكثر فعالية من اليكاند ليكاند والمعقداتليه البكتيرية لتم دراسة الفعا .المحضرة ھو رباعي التناسق ةفي المعقدات الحلقي ةان التناسق حول االيونات الفلزي) ةكيميائي-الفيزو( كشفت القياسات : ةالعام ةذات الصيغ ةمعقدات حلقي اعطىتفاعل في الطريقتين الناتج [M(L)]2 (where: M = (MnII ,CoII, NiII ,CuII , ZnII and CdII) . الفعالية البكتيرية, التراكيب دراسة, الثايوكارباميت ثنائي معقدات :المفتاحية الكلمات