基于半刚性双(噻唑基苯并咪唑)和不同羧酸的五个一维配合物的合成和表征

刘 露 靳平宁 李 英 娄慧慧 王键吉 张裕平 侯红卫 杜锦阁

(1河南科技学院化学化工学院，新乡 453003)

(2新乡医学院，新乡 453003)

(3河南师范大学化学化工学院，新乡 453007)

(4郑州大学化学与分子工程学院，郑州 450052)

(5新乡医学院三全学院，新乡 453003)

The design and construction of multifarious complexes has been a hot topic for all researchers owing to their intriguing structural motifs and potential applications in optics,magnetism,recognition,etc[1-8].Although the assembly of complexes is affected by varied factors,we haven′t stopped exploring them.In consideration of the superiority of the “mixed-ligand”synthetic strategies[9-12],which can lead to numerous graceful structures,we choose 1,4-bis(2-(4-thiazolyl)benzimidazole-1-ylmethyl)benzene(btbb)as the semirigid N-donor ligand and different multidentate O-donor carboxylates,m-phenylenediacetic acid(m-H2phda),1,3-adamantanedicarboxylic acid(H2adtda),5-tert-butylisophthalic acid (H2tbi),3-Nitro-1,2-benzenedicarboxylic acid(3-Nitro-o-H2bdc)as auxiliary ligands in the synthesis of metal-organic coordination polymer materials.Five diverse structural complexes,{[Zn(btbb)0.5(mphda)]·0.5H2O}n(1),{[Cd2(btbb)(adtda)2(H2O)]·H2O}n(2),[Mn2(btbb)(tbi)2]n(3),{[Cd(btbb)0.5(3-Nitro-o-bdc)(H2O)]·H2O}n(4)and[Cd2(btbb)(tbi)2]n(5)were prepared.The structures of 1～5 have been determined by single-crystal X-ray diffraction analyses and further characterized by infrared spectra,elemental analyses.

1 Experimental

1.1 Materials and methods

All reagents and solvents were commercially available without any further purification,except for ligand btbb,which was synthesized in accordance with the literature[13].The data of FT-IR spectra were recorded on a FTIR-7600 spectrophotometer with KBr pellets in a scale of 400～4 000 cm-1.Elemental analyses of C,H and N were performed introducing a FLASH EA 1112 analyzer.

1.2 Synthesis of{[Zn(btbb)0.5(m-phda)]·0.5H2O}n(1)

A mixture of Zn(Ac)2·2H2O(0.2 mmol),btbb(0.1 mmol),m-H2phda(0.1 mmol),NaOH(0.2 mmol)and H2O (10 mL)was placed in a 25 mL Teflon-lined stainless steel container.The mixture was sealed and heated at 180℃for three days.After the mixture was cooled to ambient temperature at a rate of 5℃·h-1,colorless crystals of 1 were obtained with a yield of 10% (based on Zn).Anal.Calcd.for C24H20ZnN3O5S(%):C,54.60;H,3.81;N,7.95.Found(%):C,54.63;H,3.79;N,7.98.IR(KBr,cm-1):3 421(s),2 988(vw),1 615(s),1 481(w),1 448(w),1 395(m),1 364(m),1 314(vw),1 272(vw),1 174(w),1 079(w),1 001(w),937(m),887(w),828(w),784(w),750(w),622(w).

1.3 Synthesis of{[Cd2(btbb)(adtda)2(H 2O)]·H 2O}n (2)

A mixture of Cd(NO3)2·4H2O(0.1 mmol),btbb(0.1 mmol),p-H2adtda(0.05 mmol),EtOH(5 mL)and H2O (5 mL)was placed in a 25 mL Teflon-lined stainless steel container.The mixture was sealed and heated at 170℃for three days.After the mixture was cooled to ambient temperature at a rate of 5℃·h-1,colorless crystals of 2 were obtained with a yield of 15%(based on Cd).Anal.Calcd.for C52H52Cd2N6O10S2(%):C,51.61;H,4.33;N,6.94.Found(%):C,51.59;H,4.30;N,6.97.IR(KBr,cm-1):3 440(s),2 908(m),2 946(m),1 616(w),1 562(s),1 479(w),1 448(s),1 386(s),1 307(s),1 241(w),1 124(w),1 041(w),931(m),889(m),823(m),744(s),713(m),622(w).

1.4 Synthesis of[Mn2(btbb)(tbi)2]n(3)

A mixture of MnCl2·4H2O(0.1 mmol),btbb(0.05 mmol),H2tbi(0.05 mmol),CH3CN(4 mL)and H2O(6 mL)was placed in a 25 mL Teflon-lined stainless steel container.The mixture was sealed and heated at 160℃for three days.After the mixture was cooled to ambient temperature at a rate of 5℃·h-1,colorless crystals of 3 were obtained with a yield of 13%(based on Mn). Anal.Calcd.for C52H44Mn2N6O8S2(%):C,59.20;H,4.20;N,7.96.Found(%):C,59.23;H,4.22;N,7.92.IR(KBr,cm-1):3 409(m),3 091(m),2 962(s),2 865(w),1 604(s),1 554(s),1 436(s),1 371(s),1 307(s),1 268(s),1 108(s),1 014(m),923(s),850(s),819(s),725(s).

1.5 Synthesis of{[Cd(btbb)0.5(3-Nitro-o-bdc)(H 2O)]·H 2O}n(4)

A mixture of Cd(NO3)2·4H2O(0.1 mmol),btbb(0.05 mmol),3-Nitro-o-H2bdc(0.05 mmol),EtOH(7 mL)and H2O (3 mL)was placed in a 25 mL Teflonlined stainless steel container.The mixture was sealed and heated at 120℃for three days.After the mixture was cooled to ambient temperature at a rate of 5℃·h-1,colorless crystals of 4 were obtained with a yield of 16%(based on Cd).Anal.Calcd.for C22H17CdN4O8S(%):C,43.32;H,2.80;N,9.18.Found(%):C,43.27;H,2.81;N,9.22.IR (KBr,cm-1):3 397(m),3 139(w),3 099(w),3 048(w),1 581(s),1 527(s),1 459(s),1 394(s),1 349(s),1 261(w),1 162(m),1 014(m),935(s),892(s),831(s),752(s),717(s).

1.6 Synthesis of[Cd 2(btbb)(tbi)2]n(5)

A mixture of Cd(NO3)2·4H2O(0.05 mmol),btbb(0.05 mmol),H2tbi(0.05 mmol),EtOH(7 mL)and H2O(3 mL)was placed in a 25 mL Teflon-lined stainless steel container.The mixture was sealed and heated at 120℃for three days.After the mixture was cooled to ambient temperature at a rate of 5 ℃·h-1,colorless crystals of 5 were obtained with a yield of 20%(based on Cd).Anal.Calcd.for C52H44Cd2N6O8S2(%):C,53.38;H,3.79;N,7.18.Found(%):C,53.35;H,3.80;N,7.16.IR(KBr,cm-1):3 432(m),3 112(w),2 958(w),1 604(m),1 550(s),1 425(s),1 386(s),1 311(w),1 116(vw),927(s),854(vw),767(s),725(m).

1.7 Crystal structural determination

The data of 1～5 were collected on a Rigaku Saturn 724 CCD diffractomer(Mo Kα,λ=0.071 073 nm)at temperature of 293(2)K.Absorption corrections were applied by using multi-scan program.The data were corrected for Lorentz and polarization effects.The structures were solved by direct methods and refined with a full-matrix least-squares technique based on F2with the SHELX-97 crystallographic software package[14].The hydrogen atoms were placed at calculated positions and refined as riding atoms with isotropic displacement parameters.Crystallographic crystal data and structure processing parameters for 1～5 are summarized in Table 1.Selected bond lengths and bond angles for 1～5 are listed in Table 2,respectively.

CCDC:1883643,1;1883644,2;1883645,3;1883646,4;1883647,5.

Table 1 Crystal data and structure refinement details for complexes 1～5

a R1=∑||F o|-|F c||/∑|F o|;b wR2=[∑w(F o2-F c2)2/∑w(F o2)2]1/2.

Table 2 Selected bond lengths(nm)and bond angles(°)for 1～5

Symmetry codes:#1:-x,-y,-z+1 for 1;#1:-x+1,-y+1,-z+1;#2:-x,-y+1,-z+1 for 2;#1:x+1,y,z for 3;#1:-x,-y+1,-z for 4;#1:x+1,y,z;#2:x-1,y,z for 5.

2 Results and discussion

2.1 Crystal structure of{[Zn(btbb)0.5(m-phda)]·0.5H 2O}n(1)

For complex 1,it consists of one crystallographically independent Znギion,half a btbb ligand,onem-phda2-ligand,and half a lattice water molecule.As illustrated in Fig.1a,Zn1ギion is six-coordinated by four O atoms of carboxylate groups (O1,O2,O3#1,O4#1)provided by two differentm-phda2-ligands,and two nitrogen atoms (N1,N2)deriving from one btbb ligand to give a octahedral coordination geometry.The distances of Zn1-N1/N2 is 0.205 1(3)/0.213 4(3)nm,while the Zn1-O bond lengths range from 0.197 8(3)to 0.242 9(3)nm.Ligand btbb exhibit asymmetricaltrans-conformation.Ndonor…N-Csp3…Csp3torsion angles of btbb is 143.613°and 143.614°,respectively.Ligandm-phda2-adopts asymmetriccis-conformation,and the angles of two-CH2-are 112.478°and 116.908°.In 1,two carboxylic groups of the “V” shape ligandmphda2-take a chelating bidentate coordination modes.The m-phda2-anions connect two adjacent Znギions using its two carboxylate groups resulting in a 22-membered rings alonga-axis (Fig.1b).The 22-membered rings are linked by btbb leading to a 1D chain along thea-axis(Fig.1c).The Zn…Zn distances across btbb ligands are 1.322 17 nm.

Fig.1 (a)Coordination environments of Znギin complex 1;(b)View of 22-membered rings constructed by two m-phda2-ligands and two Znギions along the a-axis;(c)1D chain structure containing 22-membered rings along the a-axis

2.2 Crystal structure of{[Cd 2(btbb)(adtda)2(H 2O)]·H 2O}n(2)

Single crystal X-ray diffraction analysis reveals that 2 crystallizes in monoclinic space group P21/c.The asymmetric unit of 2 consists of two Cdギions,one btbb ligand,two adtda2-anions,one coordinated water molecule and one lattice water molecule.As shown in Fig.2a,the Cd1ギion adopts a distorted octahedral geometry via coordinating with four oxygen atoms (O1,O2,O8#1)from two adtda2-anions,one oxygen atom(O3)from one coordinated water molecule and two nitrogen atoms (N1 and N3)from one btbb ligand.The Cd1-O bond distances vary from 0.216 4(7)to 0.258 3(5)nm,while the Cd1-N1/N3 bond length is 0.227 9(6)/0.243 7(6)nm,separately.While the octahedral coordination geometry of the central Cd2ギion is completed by two N atoms(N4 and N5)of one btbb ligand,and four O atoms(O4,O5,O6,O7#2)of three adtda2-anions.The Cd2-O bond distances vary from 0.219 8(6)to 0.253 8(6)nm,while the Cd2-N4/N5 bond length is 0.240 2(7)/0.232 4(6)nm.The btbb ligand adopts asymmetric trans-conformation with two different Ndonor…N-Csp3…Csp3torsion angles of 71.150°and 93.156°.The ligand adtda2-takes two different coordination modes.The first type (adtda2--Ⅰ)is that one carboxylate group of adtda2-ligand is in a bridging bidentate mode,and the other adopts a monodentate mode,whereas the two carboxylate groups of the second type(adtda2--Ⅱ)both adopt chelating bidentate modes.The adtda2--Ⅰ and adtda2--Ⅱ anions link Cdギ ions to produce a one-dimensional (1D)chain structure having a dinuclear units[Cd2(OCO)2]with a Cd…Cd separation of 0.424 84 nm (Fig.2b).Interestingly,1D Cdギ/adtda2-chain is further embellished by btbb giving rise to a more complex and beautiful 1D chain structure,and the Cd…Cd separation across btbb bridge is 1.013 00 nm(Fig.2c).

Fig.2 (a)Perspective view of the coordination environment of Cdギion in 2;(b)1D chain constructed by Cdギions and adtda2-anions having a 8-membered rings;(c)1D chain embellished by btbb

2.3 Crystal structure of[Mn2(btbb)(tbi)2]n(3)

Fig.3 (a)Coordination environments of Mnギin complex 3;(b)View of 1D Mnギ/tbi2-chain;(c)1D double chain structure of 3

The asymmetric unit of complex 3 contains two Mnギions,one btbb ligand and two tbi2-ligands in the monoclinic space group P21/c.As shown in Fig.3a,the Mn1 center is six-coordinated by four oxygen atoms(O1,O2,O3 and O6)belonging to three separated tbi2-ligands as well as two nitrogen atoms(N1 and N2)from one btbb ligand to generate a distorted octahedral coordination geometry.The Mn1-O bond distances lie in a range of 0.213 2(4)～0.234 4(4)nm,and Mn1-N1/N2 bond distances are 0.234 3(4)/0.225 4(5)nm,respectively.The Mn2 center also adopts a distorted octahedral coordination environment,which is provided by two nitrogen atoms(N4,N5)from one separate btbb and four oxygen atoms(O4,O5,O7,O8)from three tbi2-.The Mn2-O bond distances lie in a range of 0.212 0(4)～0.244 9(4)nm, and Mn2-N4/N5 bond distances are 0.233 2(6)/0.224 5(5)nm.As shown in Fig.3b,both carboxylate groups of rigid tbi2-anions adopt the mono-bidentate-bridging coordination fashion and chelating bidentate mode,separately,linking Mnギions to a 1D chain,which contains a dual-core unit[Mn2(OCO)2]with the Mn…Mn distance of 0.413 54 nm.The ligand btbb adopts asymmetric transconformation with two differenttorsion angles of 44.822°and 78.136°,and it connects two adjacent 1D Mnギ/tbi2-chain by sharing the Mnギions resulting in a 1D double chain(Fig.3c).

2.4 Crystal structure of{[Cd(btbb)0.5(3-Nitro-obdc)(H 2O)]·H 2O}n(4)

Structural analysis indicates that complex 4 is a 1D chain structure and crystallizes in the monoclinic P21/c space group.The asymmetric unit of 4 is composed of one crystallographically independent Cdギion,half a btbb ligand,and one 3-Nitro-o-bdc2-ligand,a coordination water molecule and a free water molecule.As shown in Fig.4a,the Cdギion adopts a seven-coordinated environment,which is provided by two nitrogen atoms (N1,N2)from one btbb ligand,four oxygen atoms(O1,O2,O3#1,O4#1)from two 3-Nitro-o-bdc2-anions and one oxygen atom(O7)from a coordination water molecule.The Cd-O distances are in a range of 0.234 8(5)～0.256 8(7)nm,while the Cd-N1/N2 bond length are 0.234 5(6)/2.298(5)nm,separately.The ligand btbb shows the symmetric transconformation with thetorsion angle of 162.223°.The carboxylic groups of each 3-Nitro-obdc2-anion both adopt chelating bidentate coordination modes.By this way,two 3-Nitro-o-bdc2-anions bridge two adjacent Cdギions to form a 14-membered ring along c-axis (Fig.4b).Interestingly,the neighboring 14-membered rings are connected by the transconformational btbb ligands generating the 1D chain of 4(Fig.4c),with a Cd…Cd distance of 1.334 02 nm.

Fig.4 (a)Coordination environments of Cdギin complex 4;(b)View of 14-membered rings constructed by two 3-Nitro-o-bdc2-anions and two Cdギions along the c-axis;(c)1D chain structure containing 14-membered rings along the c-axis

2.5 Crystal structure of[Cd 2(btbb)(tbi)2]n(5)

Fig.5 (a)Perspective view of the coordination environment of Cdギ ion in 5;(b)1D chain constructed by Cdギions and tbi2-anions;(c)1D double chain of 5

Single crystal X-ray diffraction analysis shows that 5 crystallizes in the space group P21/c.As shown in Fig.5a,Cd1ギion adopts a distorted octahedral coordination environment,defined by four oxygen atoms(O1#1,O2#1,O3,O5)deriving from three different tbi2-anions and two nitrogen atoms(N1,N3)originating from one btbb ligand.The distances of Cd1-N1/N3 are 0.233 7(10)/0.240 9(9)nm,while the Cd1-O bond lengths range from 0.228 7(7)to 0.248 4(7)nm.It can be clearly seen that the Cd2ギion also sits in a distorted octahedral coordination geometry defined by four oxygen atoms(O4,O6,O7#2,O8#2)from three different tbi2-anions and two nitrogen atoms(N4,N6)from one btbb ligand.The distances of Cd2-N4/N6 are 0.231 1(11)/0.243 5(13)nm,while the Cd2-O bond lengths range from 0.224 7(7)to 0.253 9(7)nm.Interestingly,there are one kind of independent tbi2-,in which one carboxylate group adopts a bisdentate chelated coordination mode and the other adopts a bridging bidentate mode.The tbi2-anions connect two Cdギ ions resulting in a Cd2(OCO)2,and Cd…Cd distance is 0.403 32 nm.The dual-core Cd2(OCO)2units are further linked and extended by tbi2-anions leading to the production of a 1D Cdギ/tbi2-chain(Fig.5b).While the btbb ligand adopts asymmetrictransconformation with two differenttorsion angles of 78.334°and 43.989°,and the bridged Cd…Cd distances along μ-btbb are 1.099 83 nm.Finally,the Cd1ギ ion and Cd2ギ ion are connected by btbb to afford a 1D double chain taking on stairstep(Fig.5c).

3 Conclusions

In short,the synergistic effect of the btbb and various carboxylates to react with Znギ/Cdギ/Mnギions gains five different complexes.Complexes 1～5 exhibit captivating structural motifs.