complexes: Syntheses, crystal structures, thermal

Journal of Molecular Structure 1059 (2014) 101–107

Contents lists available at ScienceDirect

Journal of Molecular Structure journal homepage: www.elsevier.com/locate/molstruc

One-dimensional heteropolynuclear tetracyanopalladate(II) complexes: Syntheses, crystal structures, thermal analyses and spectroscopic investigations Mehran Aksel a, Günesß Süheyla Kürkçüog˘lu b,⇑, Okan Zafer Yesßilel c, Orhan Büyükgüngör d a

Eskisßehir Osmangazi University, The Institute of Science, Department of Physics, TR-26480 Eskisßehir, Turkey Eskisßehir Osmangazi University, Faculty of Arts and Sciences, Department of Physics, TR-26480 Eskisßehir, Turkey Eskisßehir Osmangazi University, Faculty of Arts and Sciences, Department of Chemistry, TR-26480 Eskisßehir, Turkey d Ondokuz Mayıs University, Faculty of Arts and Sciences, Department of Physics, TR-55139 Samsun, Turkey b c

h i g h l i g h t s  Three new cyano-bridged heteronuclear polymeric complexes were synthesized.  The complexes are analyzed by FT-IR and Raman spectra.  The structures of 2 and 3 were determined by X-ray single crystal diffraction method.  The structures of the complexes consist of a 1D zigzag chain.  The adjacent 1D layers were extended to a 3D hydrogen-bonded network.

a r t i c l e

i n f o

Article history: Received 28 August 2013 Received in revised form 4 November 2013 Accepted 4 November 2013 Available online 21 November 2013 Keywords: Heterometallic complexes Cyano bridged complexes Tetracyanopalladate(II) complexes N,N-diethylethylenediamine complexes

a b s t r a c t Three new complexes, [Ni(deten)2Pd(l-CN)2(CN)2]n (1), [Zn(deten)2Pd(l-CN)2(CN)2]n (2) and [Cd(deten)2Pd(l-CN)2(CN)2]n (3) (deten = N,N-diethylethylenediamine), have been synthesized and characterized by elemental, spectral (FT-IR and Raman) and thermal analysis techniques. The crystal structures of the complexes 2 and 3 have been determined by X-ray single crystal diffraction. The crystallographic analysis reveals that they crystallize in the monoclinic system, space group P21/c. The Pd(II) atom is coordinated by four cyano groups. The M(II) atom is also surrounded by the two symmetry related deten ligands and the two symmetry related N atom of cyano groups. A possible decomposition of the complexes was investigated in the temperature range 30–700 °C in static air. Ó 2013 Elsevier B.V. All rights reserved.

1. Introduction For years, the coordination chemistry of cyanide-bridged metal complexes is of interest due to the unusual features of the electronic states, magnetic behaviors and photochemical properties [1–3]. Among the various classes of ligands currently employed for the generation of polymeric complexes, the cyanometallates deserve prominence for being able to generate both 1D, 2D and 3D networks depending on their organic ligands and their metallic centers [4]. Previously 1D structures of [Ni(en)2Ni(CN)4] [5], [Ni(en)2Ni(CN)4]2.16H2O [6], Ni(en)2Pd(CN)4 [7], Cu(en)2Pd(CN)4 [8] [Cu(en)2Ni(CN)4] [9] (en = ethylenediamine), [Ni(hmtd)Ni(CN)4] H2O (hmtd = N-meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene) [10], Cu(bmen)2Pd(CN)4 (bmen = ⇑ Corresponding author. Tel.: +90 222 2393750; fax: +90 222 2393578. E-mail address: [email protected] (G.S. Kürkçüog˘lu). 0022-2860/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.molstruc.2013.11.006

N,N-dimethyl-1,2-diaminoethane) [11], [Ni(bpy)2Ni(CN)4] (bpy = 2,2-bipyridine) [12], Ni(pn)2Ni(CN)4]H2O (pn = 1,2-diaminopropane) [13], [Cu(dpt)Ni(CN)4] [14], [Cu(dpt)Pd(CN)4]n (dpt = 3,3iminobispropylamine), {[Cu2(medpt)2Pd(CN)4](ClO4)23H2O}n (medpt = 3,3-diamino-N-methyldipropylamine), {[Cu2(dien)2Pd(CN)4](ClO4)22CH3OH}n (dien = diethylenetriamine) and 2D structure of {[Cu2(iPrdien)2Pd(CN)4](ClO4)22H2O}n (iprdien = Nisopropyldiethylenetriamine) [15], and molecular structure of the octanuclear complex [Cu(NH3)3Ni(CN)4]4 [16] were studied. Previously we have prepared and studied by spectroscopic, thermal properties and chemical analysis the tetracyanonickelate(II) complexes with N,N-diethylethylenediamine [17]. As a part of our continuing research on the syntheses and characterizations of complexes, we define in this study, the syntheses, spectral (FT-IR and Raman), thermal and elemental analyses of the [Ni(deten)2Pd(l-CN)2(CN)2]n (1), [Zn(deten)2Pd(l-CN)2(CN)2]n (2) and [Cd(deten)2Pd(l-CN)2(CN)2]n (3). The molecular and crystal struc-

102

M. Aksel et al. / Journal of Molecular Structure 1059 (2014) 101–107

tures of the cyano-bridged heteronuclear polymeric complexes 2 and 3 have been designated by X-ray single crystal diffraction. 2. Experimental 2.1. Material and instrumentation Nickel chloride hexahydrate (NiCl26H2O, 99%), zinc chloride (ZnCl2, 98%), cadmium chloride (CdCl2, 98%), palladium chloride (PdCl2, 99%), potassium cyanide (KCN, 96%), N,N-diethylethylenediamine (C6H16N2, 99%) were purchased from commercial sources and used as provided. Elemental analyses (carbon, hydrogen and nitrogen) were performed using a LECO CHNS-932 analyzer. The FT-IR spectra have been recorded in the 4000–400 cm1 range with a Perkin-Elmer 100 Spectrophotometer by the method of KBr pellets. The Raman spectra were recorded in the range 4000– 250 cm1 on a Bruker Senterra Dispersive Raman instrument using laser excitation of 785 nm. Perkin Elmer Diamond TG/DTA thermal analyzer was used to record simultaneous TG, DTG and DTA curves in the static air atmosphere at a heating rate of 10 K min1 in the temperature range 30–700 °C using platinum crucibles. 2.2. Crystallographic data collection and refinement Experimental data are listed in Table 1, selected bond lengths and angles and hydrogen-bond geometry are given in Tables 2 and 3, respectively. Diffraction experiments were carried out at 293 K on a Stoe IPDS diffractometer. The structures were solved by direct methods and refined using the programs SHELXS97 and SHELXL97 [18]. All non-hydrogen atoms were refined anisotropically by full-matrix least squares methods [18]. The hydrogen atoms were placed in geometrically idealized positions and refined as riding atoms. The NH2 group of deten ligand in the complex 2 is disordered over two positions with an occupation factors ratio of 0.60(3)/0.40(3). The following procedures were implemented in our analysis: data collection: X-Area, cell refinement: X-Area, data reduction: X-RED [19] program(s) used for molecular graphics were as follows: ORTEP-3 for Windows [20]; software used to prepare material for publication: WinGX [21].

Table 2 Selected geometric parameters (Å, °) for complexes 2 and 3. 2 Pd1–C7 Pd1–C8 Zn1–N1A C7–Pd1–C8 C7–Pd1–C8ii N1A–Zn1–N2 N1A–Zn1–N3

1.993 (4) 1.994 (3) 1.973 (6) 88.91 (14) 91.09 (14) 81.39 (17) 81.3 (5)

Zn1–N2 Zn1–N3

2.382 (2) 2.416 (4)

N2–Zn1–N3 N1A–Zn1–N2i N1A–Zn1–N3i N2–Zn1–N3i

88.19(10) 98.61 (17) 98.7 (5) 91.81(10)

3 Pd1–C7 Pd1–C8 Cd1–N1 C7–Pd1–C8 C7–Pd1–C8i N1–Cd1–N2 N1–Cd1–N3

1.998 (3) 1.997 (4) 2.267 (3) 90.27 (14) 89.73 (14) 102.85 (10) 94.74 (11)

Cd1–N2 Cd1–N3

2.481 (3) 2.433 (3)

N3–Cd1–N2 N1–Cd1–N2ii N1–Cd1–N3ii N2–Cd1–N3ii

91.45 (9) 102.85(10) 85.26 (11) 88.55 (9)

Symmetry codes: (i) x + 1, y + 1, z + 1; (ii) x, y + 1, z for 2 and (i) x + 2, y + 1, z + 2; (ii) x + 1, y + 1, z + 1 for 3.

Table 3 Hydrogen-bond geometry (Å, °) for complexes 2 and 3. D–H  A

D–H

H  A

D  A

D–H  A

Complex 2 N1A–H1A2  N4i

0.90

2.20

2.99 (1)

147

Complex 3 N1–H1C  N4i

0.90

2.18

2.99 (1)

151

Symmetry codes: (i) x, y – 1/2, z + 1/2 for 2 and (i) 1  x, y + 1/2, z + 3/2 for 3.

Scheme 1. The syntheses scheme of the complexes.

Table 1 Crystal data and structure refinement parameters of complexes 2 and 3.

Empirical formula Formula weight Temperature (K) Wavelength (Å) Crystal system Space group a (Å) b (Å) c (Å) b (o) V (Å3) Z Absorption coefficient (mm1) Dcalc (Mg m3) Theta range for data collection (°) Measured reflections Independent reflections Absorption correction Refinement method Final R indices [I > 2r(I)] Final R indices (all data) Goodness-of-fit on F2 Dqmax (eÅ3) Dqmin(eÅ3)

2

3

C16H32N8PdZn 508.27 293 0.71073 Mo Ka Monoclinic P21/c 8.7310 (7) 11.6986 (8) 13.1595 (11) 126.282 (5) 1083.51 (15) 2 1.95 1.558 2.59; 26.50 7054 2248 Integration Stoe X-RED [Stoe & Cie, 2001] Full-matrix least-squares on F2 Rint = 0.029 R1 = 0.034 wR2 = 0.079 1.075 0.62 0.82

C16H32 N8PdCd 555.30 293 Monoclinic P21/c 8.8162 (9) 11.9133 (11) 13.0071 (13) 126.739 (7) 1094.78 (19) 2 1.809 1.685 2.60; 26.49 6119 2246

Rint = 0.049 R1 = 0.027 wR2 = 0.062 0.973 0.61 0.45

M. Aksel et al. / Journal of Molecular Structure 1059 (2014) 101–107

2.3. Syntheses The starting material [K2Pd(CN)4]H2O was prepared by reaction between KCN and PdCl2 in the mole ratio 4:1 in aqueous solution. A mixture of a solution of PdCl2 (1.177 g, 1 mmol) in water (20 mL) and a solution of KCN (0.259 g, 4 mmol) in water (20 mL) was added dropwise with stirring at 50 °C to a solution of metal chloride (NiCl26H2O = 0.238 g, ZnCl2 = 0.136 g, and CdCl2 = 0.1838 g) in water (20 mL). The mixture was refluxed with stirring for 2 h at 50 °C in a temperature-controlled bath and then the solution was cooled to room temperature. A solution of deten (0.2324 g, 2 mmol) in ethanol (10 mL) was added dropwise upon stirring to a solution of M[Pd(CN)4]H2O (1 mmol; 0.2872 g for Ni, 0.2938

103

for Zn and 0.3409 for Cd) in water (30 mL). The solutions were refluxed with stirring for 4 h at 60 °C. The reaction mixtures were cooled to room temperature. The products were filtered off, washed with a small portion of water and ethanol, and dried on air. The chemical reactions are schematically given in Scheme 1. Elemental analyses are in good agreement with the calculated values. Yield: 0.316 g, 63% based on NiCl26H2O. Anal. Calc. for C16H32N8NiPd (1) (501.59): C, 38.31; H, 6.43; N, 22.34. Found: C, 37.81; H, 6.32; N, 22.28%. Yield: 0.274 g, 54% based on ZnCl2. Anal. Calc. for C16H32N8ZnPd (2) (508.27): C, 37.81; H, 6.35; N, 22.05. Found: C, 37.17; H, 6.21; N, 21.57%. Yield: 0.266 g, 58% based on CdCl2. Anal. Calc. for C16H32N8CdPd (3) (555.30): C, 34.61; H, 5.81; N, 20.18. Found: C, 34.52; H, 5.75; N, 20.13%.

Fig. 1. The FT-IR (a) and Raman spectra (b) of the complexes.

104

M. Aksel et al. / Journal of Molecular Structure 1059 (2014) 101–107

The m(CN) vibrations are the most important absorption bands for complexes since m(CN) vibrational peaks in the FT-IR and Raman spectra are used to reveal the bridging formation in the polymeric complexes. The vibrational wavenumbers of the 2 ½PdðCNÞ4  group for K2[Pd(CN)4]H2O and the complexes are presented in Table 5, together with vibrational assignments of 2 ½PdðCNÞ4  [22]. Whenever the cyanide groups around the palladium atom have a local D4h environment, one m(CN) band only is expected in the FT-IR spectra and two other m(CN) vibrations at higher frequencies are expected in the Raman spectra. From the FT-IR and Raman spectra of the complexes it is determined that the stretching vibration of m(C„N) has shifted to approximately 25 cm1 higher frequency (see Table 5). Two strong and sharp absorption bands about 2160 and 2140 cm1 in the FT-IR spectra of complexes can easily be attributed to bridging cyano and terminal cyano bands. As a result, in 1 the bands are at 2167 and 2144 (IR Eu), 2184 (R A1g) and 2155 (R B1g) cm1, in 2 the bands are at 2164 and 2141 (IR Eu), 2177 (R A1g) and 2165 (R B1g) cm1 and in 3 at 2164 and 2145 (IR Eu), 2171 (R A1g) and 2162 (R B1g) cm1, respectively. The observed differences in these two cyano stretching vibrations are important evidences for formation of cyano-bridged complexes with the bridging cyano wavenumbers higher than the terminal cyano [23–25]. These shifts were attrib-

3. Results and discussion Cyano bridged transition metal complexes have drawn much attention because of their structural diversity and strong tendency to construct rigid coordination bonding networks. In this study, we aimed the spectral characterization of tetracyanopalladate(II) complexes with N,N-diethylethylenediamine.

3.1. Vibrational (FT-IR and Raman) spectra The FT-IR and Raman spectra of 13 comprise bands confirming the presence of all characteristic functional groups in the prepared complexes. As can be seen from Fig. 1, the presence of bands belonging to the ligand in the FT-IR and Raman spectra of the complexes shows the existence of deten in the complexes. The vibrational spectral features of the complexes are found to be very similar to each other, indicating that they have analogous structures. The wavenumbers of deten observed in the FT-IR and Raman spectra of the complexes are given in Table 4 together with vibrational data of free deten [17]. FT-IR and Raman spectral data show that the deten ligands are coordinated to the metal ion. Table 4 The vibration wavenumbers of deten in the complexes (cm1). Assignment*

m(NH2) m(NH2) m(NH2) m(CH2) m(CH2) m(CH2) m(CH3) m(CH3) d(NH2) d(NH2) d(CH3) ds(CH2) x(CH2) x(CH2) t(CH2) t(NH2) Tertiary CN qr(CH2) qr(CH3) m(Skeletal) m(Skeletal) Primary CN m(CC) qr(CH2) x(NH2) qr(NH2) m(skeletal) + m(M-N) d(skeletal) *

deten [15]

1

2

3

Exp.

Calc.

FT-IR

R

FT-IR

R

FT-IR

R

3366 s 3288 m 3185 sh 2970 vs 2936 s 2874 s 2802 s 2756 sh 1659 vw 1591 m 1471 m 1457 m 1384 m 1371 m 1294 m 1263 w 1220 sh 1183 sh 1136 sh 1091 m 1068 m 1049 m 988 w 899 sh 847 m 768 sh 531 w 483 vw

3365 3290 – – 2912 2859 2800 2787 1626 – 1468 1455 1398 1362 1304 1256 1230 1209 1128 1097 1061 1041 991 909 828 770 531 474

3334 s 3250 s 3169 s 2970 s 2942 s 2852 m 2809 sh 2788 vw 1635 sh 1575 sh 1473 m 1447 m 1391 m 1379 s 1309 m 1279 m 1234 sh 1184 w 1120 s 1095 sh 1070 s 1049 m 1004 m 898 m 858 vw 778 sh 551 sh 493 m

3337 w 3258 vw 3171 vw 2973 w 2938 s 2855 w – 2779 vw – 1601 vw – 1454 w – 1377 vw 1304 vw 1279 vw 1243 vw 1196 vw 1123 vw 1093 vw 1076 w 1048 vw 1004 vw 894 w 857 w 780 vw 530 vw 481 w

3332 m 3281 sh – 2980 m 2942 m 2876 m 2808 sh 2757 sh 1632 sh 1599 m 1474 m 1460 m 1395 m 1268 w 1296 sh 1253 m 1228 sh 1198 m 1127 m 1083 m 1067 m 1034 m 997 m 901 m 828 m 774 sh 534 vw 489 m

3321 vw – – 2976 vw 2945 w 2886 vw 2802 vw 2757 vw 1634 sh 1593 vw 1479 sh 1465 s 1392 vw 1369 vw 1294 vw 1263 vw 1238 vw 1198 vw 1139 vw 1093 s 1066 m 1045 w 985 vw 907 m 829 vw 751 s 552 w 489 w

3329 s – 3156 s 2981 s 2941 s 2875 s 2801 sh 2771 vw 1630 sh 1601 vs 1474 m 1458 m 1393 m 1367 w 1296 m 1251 sh 1222 m 1195 sh 1121 m 1082 m 1070 m 1034 m 994 s 904 m 843 w 765 sh 532 sh 486 m

3329 vw 3288 vw 3184 vw 2981 w 2935 w 2873 w 2800 vw 2772 vw 1598 vw 1472 vw 1462 vw 1386 vw 1372 vw 1294 vw 1253 vw 1220 vw 1197 vw 1121 vw 1080 vw 1068 vw 1032 vw 1032 vw 1001 vw 902 vw 846 vw 762 vw 531 vw 485 vw

Abbreviations used: m stretching, d deformation, x wagging, t twisting, r rocking, s strong, m medium, w weak, sh shoulder, v very.

Table 5 The FT-IR and Raman wavenumbers of the [Pd(CN)4]2 unit in the complexes (cm1). Assignments [22]

[Pd(CN)4]2

K2[Pd(CN)4]H2O

1

2

3

A1g, m1, m(CN) B1g, m4, m(CN) Eu, m8, m(CN) Eu, m(C13N) Eu, m9, m(PdC) A1g, m2 Eu, m10, d(PdCN)

(2161) s (2147) w 2142 s 2097 w 503 w (430) m –

(2169) vs (2159) s 2135 vs 2112 sh 486 w (436) m 393 m

(2184) vs (2155) s 2167 vs, 2144 vs 2103 w 493 m (420) w 402 w

(2177) vs (2165) sh 2164 m, 2141 vs 2102 w 490 m (442) vs 403 sh

(2171) vs (2162) s 2164 m, 2145 s 2102 w 488 m (431) m 404 sh

Abbreviations used; s strong, m medium, w weak, sh shoulder, br broad, v very. The symbols t, d and p refer to valence, in-plane and out-of-plane vibrations, respectively. Raman spectra are given in parentheses.

M. Aksel et al. / Journal of Molecular Structure 1059 (2014) 101–107

105

Fig. 2. An ORTEP-3 drawing of complex 2 with the atom numbering scheme. The NH2 group of the deten ligand is disordered and displacement ellipsoids are drawn at the 30% probability level. Symmetry code: [(i)x, 1  y, z; (ii) 1  x, 1  y, 1z].

uted to the kinematic coupling placing a mechanical constraint upon the bridging cyano by the second metal [17,26,27]. In the other words, such frequency shifts are attributed to the mechanical coupling of the internal modes of Pd(CN)4 with the M–NC vibrations (M = Ni, Zn or Cd). It follows that the N-termini of the Pd(CN)4 group are bound to a M atom in the complexes. In-plane bending vibration band d(Pd-CN) shifts to a higher frequency to support the m(CN) stretching vibration band. The results from FT-IR and Raman spectral data were compared with the X-ray data and can be useful for the diagnosis of the structures of other cyano complexes when single crystals are not available. 3.2. Crystal structures of [M(deten)2Pd(l-CN)2(CN)2]n (M = Zn(II) (2) and Cd(II) (3)) The complexes 2 and 3 are isomorphous (Figs. 2 and 3). Hence, only the structure of complex 2 is described in detail. X-ray diffraction analysis reveals that complex 2 crystallizes in mono-

Fig. 4. View of the unit cell of 3 formed by N–H  N hydrogen bonds (non-hydrogen bonding hydrogen atoms are omitted for clarity).

clinic crystal system, space group P21/c. As shown in Fig. 2, the asymmetric unit contains one Zn(II) and one Pd(II) ions, two deten ligands and four cyano ligands. The structure of 2 consist of a 1D zigzag chain in which the Zn(II) and Pd(II) ions are linked by cyano ligands. The Zn1 ion has a distorted octahedral coordination sphere and is coordinated by two nitrogen atoms from two cyano ligands and four nitrogen atoms from two bidentate deten ligands. The Pd1 ion has a square planar geometry and is coordinated by four carbon atom from four cyano ligands. The Zn–N (2.382 (2) and 2.416 (4) Å), Cd–N (2.481 (3) and 2.433 (3) Å) and Pd–C (1.993 (4), 1.994 (3), 1.998 (3) and 1.997 (4) Å) bond distances are similar that found in the [Zn(hydet-en)2Pd(CN)4] (Zn1–N1 2.215 (2) Å) and Pd1–C5 1.988 (2) Å) and [Cd(hydet-en)2Pd(CN)4] (Cd1–N 12.360 (3) and Pd1–C5 1.987(2) Å) [25]. The intrachain Zn1  Zn1i distance is 10.475 Å, whereas the shortest interchain Zn1  Zn1ii distance is 8.819 Å ((i) 1 + x, y, 1 + z and (ii) 1  x, 1/2 + y, 1.5  z). These bond distances compare well to the literature values [8,25]. Adjacent 1D chains are further extended to a 3D hydrogenbonded network through the intermolecular NH  N hydrogen bond between the amine group of deten ligand and cyano ligand [N1A  N4iii = 2.99 (1) Å and N1AH1A2  N4iii = 147°] (Fig. 4).

3.3. Thermal analyses

Fig. 3. An ORTEP-3 drawing of complex 3 with the atom numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. Symmetry code: [(i) 2  x, 1  y, 2  z; (ii) 1  x, 1  y, 1  z].

Thermal decomposition behaviors of the complexes were performed in static atmosphere of air in the temperature ranges of 30–700 °C. Thermal decomposition curves of the complexes are presented in Figs. 5–7, respectively. The complex 1 exhibits one decomposition stage, while complexes 2 and 3 exhibit three decomposition stages. The complexes 1, 2 and 3 are thermally stable up to 205, 113 and 136 °C, respectively. In the first and last stage between 205 and 379 °C for 1 (found 67.80, calcd. 67.08%), the successive two deten ligands and four cyano ligands decomposition process is an exothermic contribution is also observed in the DTA curves of 1. The first stages of complexes 2 and 3 are related to the successive release of one deten ligand by giving endothermic effect (found 24.02, calcd. 22.86% for 2, found 21.70, calcd.

106

M. Aksel et al. / Journal of Molecular Structure 1059 (2014) 101–107

Fig. 5. The TG, DTG and DTA curves of 1.

Fig. 6. The TG, DTG and DTA curves of 2.

Fig. 7. The TG, DTG and DTA curves of 3.

M. Aksel et al. / Journal of Molecular Structure 1059 (2014) 101–107

20.92% for 3). In addition, the second stage between 204 and 326 °C for 2, 242 and 386 °C for 3 corresponds to the endothermic elimination one deten ligands with a mass loss of 19.55% and 22.88%, respectively (calcd. 22.86 and 20.92%). The following stage involves the exothermic decomposition of cyano ligands. The final solid products of thermal decomposition were identified as MO and Pd (M = Ni(II), Zn(II) and Cd(II), found 34.88, calcd. 36.10% for 1, found 39.58, calcd. 36.95% for 2 and found 39.95, calcd. 42.28% for 3).

4. Conclusion Three new cyano-bridged heteronuclear polymeric complexes have been synthesized and characterized. Structures of the complexes were determined by using vibrational (FT-IR and Raman) spectroscopy, thermal and elemental analysis techniques. The structures of complexes 2 and 3 certainly were also designated by X-ray single crystal studies. The structures of the complexes consist of a 1D zigzag chain in which the Zn(II) or Cd(II) and Pd(II) ions are linked by cyano ligands. The formation of cyanide bridges is evident from the FT-IR and Raman spectra by the appearance of m(CN) shifts. According to the spectral data, the formation of the cyano bridge shifts m(CN) towards higher frequencies.

Appendix A. Supplementary material CCDC 833236 & 833237 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge via http://www.ccdc.cam.ac.uk/conts/retrieving.html (or from the CCDC, 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44 1223 336033; e-mail: [email protected]). Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/ j.molstruc.2013.11.006.

107

References [1] N.W. Alcock, A. Samotus, J. Szklarzewicz, J. Chem. Soc. Dalton (1993) 885–889. [2] D.W. Knoeppel, S.G. Shore, Inorg. Chem. 35 (1996) 5328–5334. [3] J. Cernak, M. Orendac, I. Potocnak, J. Chomic, A. Orendacova, J. Skorsepa, A. Feher, Coord. Chem. Rev. 224 (2002) 51–66. [4] L. Triscikova, J. Chomic, K.S. Abboud, J.H. Park, M.W. Meisel, J. Cernak, Inorg. Chim. Acta 357 (2004) 2763–2768. [5] J. Cernak, J. Chomic, D. Baloghova, M. Dunajjurco, Acta Crystallogr. C 44 (1988) 1902–1905. [6] J. Cernak, I. Potocnak, J. Chomic, M. Dunajjurco, Acta Crystallogr. C 46 (1990) 1098–1100. [7] J. Cernak, J. Lipkowski, E. Cizmar, A. Orendacova, M. Orendac, A. Feher, M.W. Meisel, Solid State Sci. 5 (2003) 579–585. [8] J. Cernak, J. Skorsepa, K.A. Abboud, M.W. Meisel, M. Orendac, A. Orendacova, A. Feher, Inorg. Chim. Acta 326 (2001) 3–8. [9] J. Lokaj, K. Gyerova, A. Sopkova, J. Sivy, V. Kettmann, V. Vrabel, Acta Crystallogr. C 47 (1991) 2447–2448. [10] G.J. Gainsford, N.F. Curtis, Aust. J. Chem. 37 (1984) 1799–1816. [11] J. Hanko, M. Orendac, J. Kuchar, Z. Zak, J. Cernak, A. Orendacova, A. Feher, Solid State Commun. 142 (2007) 128–131. [12] J. Cernak, K.A. Abboud, Acta Crystallogr. C 56 (2000) 783–785. [13] S.Z. Zhan, D. Guo, X.Y. Zhang, C.X. Du, Y. Zhu, R.N. Yang, Inorg. Chim. Acta 298 (2000) 57–62. [14] Z. Smekal, I. Cisarova, J. Mrozinski, Polyhedron 20 (2001) 3301–3306. [15] S.C. Manna, S. Konar, E. Zangrando, J. Ribas, N.R. Chaudhuri, Polyhedron 26 (2007) 2507–2516. [16] C. Janiak, H.P. Wu, P. Klufers, P. Mayer, Acta Crystallogr. C 55 (1999) 1966– 1969. [17] G.S. Kürkçüog˘lu, T. Hökelek, M. Aksel, O.Z. Yesßilel, H. Dal, J. Inorg. Organomet. Polym. 21 (2011) 602–610. [18] G.M. Sheldrick, Acta Crystallogr. A 64 (2008) 112–122. [19] Stoe & Cie, X-AREA (Version 1.18), X-RED32 (Version 1.04). Stoe & Cie, Darmstadt, Germany, 2002. [20] L.J. Farrugia, J. Appl. Crystallogr. 30 (1997) 565. [21] L.J. Farrugia, J. Appl. Crystallogr. 32 (1999) 837–838. [22] L.H. Jones, Inorganic Vibrational Spectroscopy, Dekker, New York, 1971. [23] A.D. Legendre, A.E. Mauro, M.A. de Oliveira, M.T.D. Gambardella, Inorg. Chem. Commun. 11 (2008) 896–898. [24] S.C. Manna, J. Ribas, E. Zangrando, N.R. Chaudhuri, Polyhedron 26 (2007) 3189–3198. [25] A. Karadag˘, A. Bulut, A. Sßenocak, I. Uçar, O. Büyükgüngör, J. Coord. Chem. 60 (2007) 2035–2044. [26] G.S. Kürkçüog˘lu, T. Hökelek, O.Z. Yesßilel, S. Aksay, Struct. Chem. 19 (2008) 493– 499. [27] G.S. Kürkçüog˘lu, O.Z. Yesßilel, I. Çaylı, O. Büyükgüngör, Z. Kristallogr. 224 (2009) 493–498.