Ionothermal Syntheses and Characterizations of New Open-Framework Metal Borophosphates
Inorg.Chem.2011,50,1073–10781073
DOI:
10.1021/ic101713y
Ionothermal Syntheses and Characterizations of New Open-Framework Metal Borophosphates
Tan Su,?Hongzhu Xing,?Jin Xu,?Jihong Yu,*,?and Ruren Xu ?
?
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry,College of Chemistry,
Jilin University,Changchun 130012,P.R.China,and ?College of Chemistry,Northeast Normal University,Changchun 130024,P.R.China
Received August 24,2010
Three new open-framework metal borophosphates,[Na 6Co 3B 2P 5O 21Cl ]3H 2O (JIS-4),K 5Mn 2B 2P 5O 19(OH )2(JIS-5),(NH 4)8[Co 2B 4P 8O 30(OH )4](JIS-6),have been prepared under ionothermal conditions using ionic liquid 1-ethyl-3-methylimidazolium ([Emim ]Br )as the solvent.They are the first examples of metalloborophosphate prepared by the ionothermal method.Their structures are determined by single-crystal X-ray diffraction.The 3-D open framework of JIS-4is made of CoO 5Cl octahedra,CoO 5square pyramids,and PO 4and BO 4tetrahedra forming 12-ring channels along the [010]direction.It is noted that JIS-4is the first 3-D open-framework structure in the family of borophosphate with the B/P ratio of 2/5,which features a borophosphate cluster anionic partial structure.Such cluster anionic partial structures connect with MnO 6octahedra and MnO 5trigonal bipyramids resulting in the formation of the 2-D layer structure of JIS-5with the same B/P ratio as JIS-4.The 2-D layer structure of JIS-6belongs to the largest family of borophosphate with a B/P ratio of 1/2which features a unique
1-D chain anionic partial structure.Crystal data for JIS-4,orthorhombic,Pnma ,a =14.0638(8)A
?,b =9.8813(7)A
?,c =14.0008(10)A ?,V =1945.7(2)A ?3,and Z =2;for JIS-5,monoclinic,P 21/n ,a =14.4939(3)A
?,b =9.2539(3)A ?,c =14.8031(4)A ?,β=101.4600(10)°,V =1945.88(9)A ?3,and Z =4.For JIS-6,triclinic,P 1,a =9.6928(3)A ?,b =9.8747(3)A ?,c =10.0125(2)A ?,R =62.057(2)°,β=82.456(2)°,γ=76.095(2)°,V =821.60(4)A
?3,and Z =1.Introduction
Inorganic open-framework compounds are of immense
interest in chemistry and materials science because of their applications as catalysts,ion-exchangers,or molecular sieves.1-6Extensive research has focused on the open-framework metal borophosphates in recent years owing to their diverse structural architectures and interesting properties in optics and electrooptics.7,8Since the first borophosphate,(C 2H 10N 2)[CoB 2P 3O 12(OH)],with an open framework struc-ture was reported in 1996,9a broad spectrum of borophos-phates with various dimensionalities and stoichiometries have been prepared using hydro-/solvothermal and boric
acid flux methods with or without organic amines as tem-plates.10-15The structural chemistry of borophosphates features diverse B/P ratios and various anionic partial struc-tures (containing only boron and phosphorus polyhedra)such as oligomeric units,chains,ribbons,layers,and 3-D frameworks.7,10However,it is worth noting that,in the family of open-framework borophosphates,compounds with B/P ratio of 2/5comprises only two reported structures.8The 3-D framework anionic partial structures are rarely reported.16-18Besides the various anionic partial structures,transition metal ions play important roles in the formation of
*To whom correspondence should be addressed.E-mail:jihong@https://www.sodocs.net/doc/e115734833.html,.Fax:t86-431-85168608.Tel:t86-431-85168608.
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1074Inorganic Chemistry,Vol.50,No.3,2011Su et al.
borophosphate structures and show rich diversity of the coordination geometries and coordination environments.It is interesting to observe a pentacoordinated square pyramid for vanadium10,19and copper ions.20Considering the frame-work elements,two chlorine substituted compounds,(C6H14-N2){Zn[ZnB2P4O15(OH)2]3(C6H13N2)Cl}21and(C4H16N3)-[CdClB2P3O12(OH)],22have been reported where the chlor-ine ligands instead of oxygen are observed in the coordination
sphere of zinc and cadmium ions,respectively.It is noted that,up to date,even for the whole family of borophosphates, only a small number of compounds are known in which the oxoligands of the complex anions are substituted.23,24 Open-framework materials are typically synthesized using hydro-/solvothermal methods.Recent research has revealed that the ionothermal synthesis,25,26i.e.,the use of ionic liquid as solvent and sometimes template or structure-directing agent,is a promising technique in preparing inorganic open frameworks with novel structures and special properties,which are diffi-cult to obtain by routine hydro-/solvothermal methods.27-29 Ionothermal synthesis is currently receiving great attention by chemists because of the different chemistry of ionic liquid solvent system compared to that of the traditionally used water/ alcohols in hydro-/solvothermal conditions.Many more open-framework compounds with new structural architectures,new compositions,and interesting properties have been prepared by ionothermal method.Very recently,we reported the ion-othermal synthesis of an open-framework nickel phosphite (JIS-3)with extra-large18-ring channels and magnetic aniso-tropy.30However,ionothermal synthesis of borophosphates is rarely reported.31-33Considering the important role of transi-tion metal ions played in the borophosphate system,it is expected that novel metal borophosphates with unique structure features would be prepared by the ionothermal method.
Here,we report the first ionothermal syntheses and char-
acterizations of three new open-framework metal boropho-
sphates,[Na6Co3B2P5O21Cl]3H2O(JIS-4),K5Mn2B2P5O19-(OH)2(JIS-5),and(NH4)8[Co2B4P8O30(OH)4](JIS-6),using
the ionic liquid1-ethyl-3-methylimidazolium([Emim]Br)as
solvent.They all adopt new framework topologies exhibiting
unique structural features unprecedented in the family of
borophosphates.
Experimental Section
Synthesis and Physical Characterizations.All three compounds
were prepared under ionothermal conditions using the ionic liquid
1-ethyl-3-methylimidazolium([Emim]Br)as solvent.Other chemi-
cals including CoCl236H2O,Co(NO3)236H2O,MnCl234H2O, H3BO3,(NH4)2HPO4,K2HPO433H2O,and NaH2PO432H2O were used as received in reagent grade.The mixed starting reagents were heated in15mL Teflon-lined autoclaves under autogenous pressure at200°C for several days followed by cooling to room temperature.The products were filtered off,washed with deionized water,rinsed with ethanol,purified ultrasonically,and dried in vacuum desiccators at ambient temperature.
Single-phased dark-purple crystals of[Na6Co3B2P5O21Cl]3H2O (JIS-4)with a yield of～70%(based on Co)were obtained from a reaction mixture of CoCl236H2O(0.238g),NaH2PO4(0.31g), H3BO3(0.062g),and[Emim]Br(1.0g),in a molar ratio of 1:2:1:5.24for10-20days.When the amount of H3BO3was increased to2mmol(0.124g)in the above reaction,pink platelike crystals of NaCoH2BP2O934were obtained as a single-phase product with a yield of～75%(based on Co).In the synthesis for K5Mn2B2P5O19(OH)2(JIS-5),MnCl234H2O(0.20g),K2HPO43 3H2O(0.20g),and H3BO3(0.06g)was mixed with1.0g[Emim]Br in a molar ratio of1:0.9:1:5.24.Light-pink platelike crystals of JIS-5together with a small amount of powder(about15%)was obtained after5days of crystallization.It was not successful in the attempts to prepare JIS-5analog using other alkali metal ions besides the potassium ion.As for(NH4)8[Co2B4P8O30(OH)4](JIS-6),a mixture composed of Co(NO3)236H2O(0.29g),(NH4)2HPO4 (0.4g),H3BO3(0.124g),and1.0g[Emim]Br with a molar ratio of 1:3:2:5.24gave rise to the pink tetragonal-stick crystals of JIS-6 together with purple powder(about20%).When the amount of (NH4)2HPO4was increased to4mmol(0.53g),another platelike smaller crystalline phase was found to become a major product. However,the crystal was too small for the single-crystal data collection,and the phase was contaminated with unknown pow-ders.All the following physical characterizations of JIS-5and JIS-6 were based on the picked out crystals.All three compounds can also be obtained using ionic liquid1-methyl-3-butylimidazolium bromide([Bmim]Br)as the solvent instead of[Emim]Br.
The chemical formulas of these three compounds were pri-
marily determined on the basis of single-crystal structure anal-
ysis.Powder X-ray diffraction(XRD)and in situ temperature dependent X-ray diffraction data were both collected on a Rigaku D-Max2550diffractometer with Cu K R radiation(λ=1.5418A) to confirm their phase identity and thermal stability,respectively. The diffraction patterns were consistent with those calculated from the structures determined by single-crystal X-ray diffraction (Figure S1,Supporting Information).The in situ temperature dependent X-ray diffraction of JIS-4was performed at a heating rate of10°C min-1,and the data were collected at a rate of 4°min-1.Inductively coupled plasma(ICP)analysis performed on a Perkin-Elmer Optima3300DV ICP instrument gave the contents of the elements in the three structures(Table S1,Supporting Information),which are consistent with the single-crystal X-ray analysis.The presence of Cl in JIS-4was confirmed by energy-dispersive spectroscopy(EDS)analysis performed on a Hitachi, S-4300field emission scanning electron microscope.
(19)(a)Bontchev,R.P.;Do,J.;Jacobson,A.J.Inorg.Chem.2000,39, 3320.(b)Warren,C.J.;Haushalter,R.C.;Rose,D.J.;Zubieta,J.Chem.Mater. 1997,9,2694.
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(28)See,for example:(a)Chen,S.M.;Zhang,J.;Bu,X.H.Inorg.Chem. 2008,47,5567.(b)Hogben,T.;Douthwaite,R.E.;Gillie,L.J.;Whitwood,A.C. CrystEngComm2006,8,866.(c)Ji,W.J.;Zhai,Q.G.;Hu,M.C.;Li,S.N.; Jiang,Y.C.;Wang,https://www.sodocs.net/doc/e115734833.html,mun.2008,11,1455.(d)Lin,Z.J.;Li, Y.;Slawin,A.M.Z.;Morris,R.E.Dalton Trans.2008,3989.(e)Zhang,J.;Chen, S.M.;Bu,X.H.Angew.Chem.,Int.Ed.2008,47,5434.
(29)Himeur,F.;Allan,P.K.;Teat,S.J.;Goff,R.J.;Morris,R.E.; Lightfoot,P.Dalton Trans.2010,6018.
(30)Xing,H.;Yang,W.;Su,T.;Li,Y.;Xu,J.;Nakano,T.;Yu,J.;Xu,R. Angew.Chem.,Int.Ed.2010,49,2328.
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Article Inorganic Chemistry,Vol.50,No.3,20111075
Crystals with dimensions of0.15?0.08?0.08mm3for JIS-4, 0.1?0.1?0.09mm3for JIS-5,and0.15?0.08?0.07mm3for JIS-6were selected for data collection at298(2K.The data were collected on a Siemens SMART CCD diffractometer using graphite-monochromated Mo K R radiation(λ=0.71073A). Data processing was accomplished with the PROCESSAUTO processing program.On the basis of systematic absences and statistics of intensity distribution,the space group was determined to be Pnma for JIS-4,P21/n for JIS-5,and P1for JIS-6.Direct methods were used to solve the structure using the SHELXTL crystallographic software package.35All framework atoms Co, Mn,B,P,Cl,and O and guest atoms K,Na,and Ow could be unambiguously located,whereas the hydrogen atoms cannot be found on the Fourier difference maps for all three compounds.The nonhydrogen atoms were refined anisotropically.The final cycle of refinement,including the atomic coordinates,anisotropic thermal parameters for all nonhydrogen atoms,and isotropic thermal parameters for H atoms,converged at R1=0.0511and wR2= 0.1637for JIS-4,R1=0.0352and wR2=0.1241for JIS-5,and R1=0.0523and wR2=0.1396for JIS-6.Crystallographic data are listed in Table1,and ORTEP drawings with atomic labeling are given in the Supporting Information(Figure S2). Thermogravimetric analyses of the three compounds,using a Perkin-Elmer TGA-7thermogravimetric analyzer,were per-formed on the powder samples at a heating rate of10°C min-1 in a flow of air(Figure S3,Supporting Information).For JIS-4, a two-step mass loss of6.1%(calcd:6.2%,by assuming a total loss of H2O and HCl)was observed in the TG curve.The mass loss of4.2%at the last step mainly occurred in the temperature range of450-650°C and can be attributed to the loss of HCl (calcd:4.1%),and the mass loss of1.9%before450°C can be ascribed to the removal of water molecules(calcd:2.1wt%)in the product.The in situ temperature dependent X-ray diffrac-tion patterns of JIS-4show that the framework of JIS-4is thermally stable up to600°C(Figure S4,Supporting Information). Both JIS-5and JIS-6shows mainly a one-step mass loss in a different temperature range.As indicated in the TG curve of JIS-5, a mass loss of3.0%(calcd:2.5%)in the range of300-500°C is attributed to the removal of the P-OH terminal group,whereas a total mass loss of15.9%(calcd:16.4%,by assuming a total loss of NH3and H2O)in the range of340-650°C for JIS-6can be ascribed to the decomposition of extra-framework ammonium cations and P-OH terminal groups.
Results and Discussion
JIS-4consists of an anionic open framework[Co3B2P5-O21Cl]6-which is charge balanced by sodium cations in the structure.The asymmetric unit of JIS-4(Figure S2,Supporting Information)contains three crystallographically distinct Co atoms,three crystallographically distinct P atoms,and one crystallographically distinct B atom.The Co(1)atoms are in a distorted octahedral environment with five Co-O bonds (2.084(6)-2.117(6)A)and a Co-Cl bond(2.591(3)A).Both Co(2)and Co(3)atoms are in a square pyramidal coordination with the Co-O bond lengths varying in the range of2.012-(5)-2.126(5)A.The P(1)and P(2)atoms are tetrahedrally coordinated to four oxygens shared by adjacent cobalt atoms whereas P(1)atom shares oxygens with two B atoms and two pentacoordinated Co atoms.The tetrahedrally coordinated B atom coordinates to threeμ-O atoms shared by adjacent P atoms,oneμ3-O shared by both mirror related boron atoms.The B-O bond distances are in the range of1.457(9)-1.509(8)A.
The structure of JIS-4is built up from the connection of CoO5Cl octahedra,CoO5square pyramids,and PO4and BO4 tetrahedra,giving rise to a3D open framework.The structure features a2D cobalt-oxygen/chloride phosphate layer contain-ing CoO5Cl octahedra,CoO5square pyramids,and PO4 groups.The cobalt-oxygen/chloride phosphate layers perpen-dicular to the c axis are further connected by borate dimers to form the3-D open framework(Figure1a),possessing12-ring channels along the[100]direction(Figure1b)and8-ring channel along the[010]direction(Figure1c).The anionic partial structure[B2P5O21]11-of JIS-4is also the fundamental building unit(FBU),open-branched dreier-single ring hepta-mer(70:[<30>]0|0|0|0|,where0represents tetrahedron),8 shown in Scheme1a.The four pendent P-centered tetrahedra in the three-membered ring of the heptamer further connect to CoO5Cl octahedron forming cobalt-centered borophosphate
Table1.Crystal Data and Structure Refinement for[Na6Co3B2P5O21Cl]3H2O(JIS-4),K5Mn2B2P5O19(OH)2(JIS-5),and(NH4)8[Co2B4P8O30(OH)4](JIS-6)
JIS-4JIS-5JIS-6 formula Na6H2Co3B2P5O22Cl K5H2Mn2B2P5O21N8H36Co2B4P8O34 fw880.67817.851064.94
crystal system,space group orthorhombic,Pnma monoclinic,P21/n triclinic,P1
a(A)14.0638(8)14.4939(3)9.6928(3)
b(A)9.8813(7)9.2539(3)9.8747(3)
c(A)14.0008(10)14.8031(4)10.0125(2)
R(deg)9090.0062.057(2)
β(deg)90101.4600(10)82.456(2)
γ(deg)9090.0076.095(2)
V(A3)1945.7(2)1945.88(9)821.60(4)
Z241
D calcd(g cm-3) 2.541 2.792 2.152
μ(mm-1;Mo K R) 4.590 2.885 1.532
F(000)14111592522
θrange(deg) 2.05-28.32 1.80-28.30 2.17-28.29 reflections collected13526130836042
unique data256348354853
restraints/parameters0/1930/3223/514
goodness of fit on F2a0.9580.899 1.001
R1b[i>2σ(i)]0.05110.03520.0523
wR2c(all data)0.16370.12410.1396
a Goodness-of-fit S=[P
w(F o2-F c2)2/(n-p)]1/2,where n is the number of reflections and p is the number of parameters.b R1=
P
||F o|-|F c||/
P
|F o|.
c wR
2=[
P
(w(F o2-F c2)2)/
P
(w(F o2)2)]1/2.
1076Inorganic Chemistry,Vol.50,No.3,2011Su et al.
the 3-D framework.It is noted that,to the best of our knowl-edge,the square pyramidal Co ions presented in JIS-4have not been observed in the family of open-framework boropho-sphates and the concomitant halide substituted coordinated metal ions are also rare.23,24
As mentioned above,JIS-4can only be prepared in a narrow region with a small amount of water in the ionothermal system.At low water concentration,the strong hydrogen bonding of the water molecules in ionic liquids leads to water being less reactive than similar amounts in other solvents,which would cause the different chemistry of ionothermal condition in contrast to the routine hydro/solvothermal condi-tions.36It has been demonstrated that the amount of water presented in the ionothermal condition is important for the resultant phase.In an attempt to understand the role of water in the reaction of JIS-4,a series of experiments were designed in which the amount of water was increased gradually.It was
found that JIS-4pure phase can be obtained when less than 20μL of deionized water (1.11?10-3mmol)was added in the above reaction system,and the crystallization time would shortened correspondingly by up to 4days.With the increase of additional water,cobalt borophosphate NaCoH 2BP 2O 934was obtained.The results show that a small amount of water in the reaction system of JIS-4is vital both for the crystallization rate and the phase selectivity in ionothermal synthesis,which is in accordance with the phenomena observed in the ionother-mal synthesis of aluminophosphate molecular sieves.JIS-4cannot be obtained either using H 3PO 4as the phosphorus source or using some kinds of alcohol (e.g.,ethylene glycol and n-butyl alcohol)as solvents in our experiments.We also studied the ion-exchange property of Na tin JIS-4,which showed no obvious ion-exchange capacity for other ions such as NH 4tand Li tions.
JIS-5possesses a 2-D layer structure with the same anionic 11-Figure 1.(a)View showing that the framework of JIS-4consists of cobalt phosphate layers which are pillared by borate dimers.The Na atoms and H 2O molecules are ommited for clarity.(b)12-ring channels along the [100]direction and (c)8-ring channel along the [010]direction in the structure where the μ-O atoms,Na atoms and H 2O molecules are omitted for clarity (μ3-O atoms are kept).
Scheme 1.How the Anionic Partial Structure and the Different Transition Metal Ions Connect in the Structure of JIS-4a
a
(a)Anionic partial structure of open-branched dreier-single ring heptamer with a B/P ratio of 2/5;(b)the single Co centered borophosphate cluster;(c)the cluster is connected by square pyramids.
Article Inorganic Chemistry,Vol.50,No.3,20111077
crystallographically distinct Mn atoms,five crystallographi-cally distinct P atoms,and two crystallographically distinct B atoms.The Mn(2)atom is in a distorted octahedral environ-ment sharing fiveμ-O atoms with five P atoms and oneμ3-O with two boron atoms,while the Mn(1)atom in a distorted trigonal bipyramidal environment shares five bridging oxy-gen atoms with five P atoms.The Mn-O bond lengths vary in the range of2.062(2)-2.268(2)A.Five crystallographi-cally distinct P atoms are each tetrahedrally coordinated to four oxygen atoms but in different fashions.P(1)atoms share four bridging oxygen atoms with two Mn(2)octahedra,one Mn(1)trigonal bipyramid,and one B atom.P(2)atoms
share twoμ-O atoms with B atoms and oneμ-O atom with Mn(1)trigonal bipyramid,leaving one terminal P(2)d O(9) group with bond length of1.497(3)A.P(3)atoms share four bridging oxygen atoms with two Mn(1)trigonal bipyramids, one Mn(2)octahedron,and one boron atom.P(4)atom shares bridging atoms with one Mn(1),Mn(2),and B atoms, leaving one terminal P(4)d O(8)group with bond length of 1.509(3)A,while P(5)atoms share two bridging atoms with one Mn(2)and B atoms,leaving two terminal groups of P(5)-O(1)H with bond length of1.575(3)A and P(5)d O(10) with bond length of1.493(3)A.The tetrahedrally coordi-nated B atom coordinates to threeμ-O atoms shared by adjacent P atoms,oneμ3-O shared by both mirror related boron atoms.The B-O bond lengths range from1.423(4)to 1.504(4)A.
JIS-5consists of2-D layer anionic framework[Mn2B2-
P5O19(OH)2]5-containing a distorted8-ring in the structure
(Figure2).Potassium cations located between adjacent layers
compensate the negative charge of the anionic framework.
The Mn-centered borophosphate clusters(Figure2b)similar to the Co-centered borophosphate clusters in JIS-4can also be
observed.It is interesting to note that both JIS-4and JIS-5
possess the same B/P ratio of2/5.Although a large number of
borophosphate structures have been synthesized with various B/P ratios,up to date,the number of borophosphates with
molar ratio of B/P=2/5is still very small with2-D layered
compound(N2C3H5)3.8(H3O)1.2[(VO)4B2P5O22]30.3H2O(1) and0-D cluster(C6H14N2)2[VB2P5O17(OH)5]3H2O3H3PO4 (2),as known examples.19a,37The two vanadium boropho-
sphates in both cases were prepared under hydrothermal
conditions with organic amines as https://www.sodocs.net/doc/e115734833.html,pounds1
and2have two different kinds of anionic partial structure,
i.e.,open-branched heptamer(70:[30]0|0|0|0|)and open-branched dreier-single ring heptamer(70:[<30>]0|0|0|0|) as FBUs,respectively.8Both JIS-4and JIS-5possess the anionic partial structure[B2P5O21]11-of open-branched dre-ier-single ring heptamer which is the same as that in compound 2.It is worth noting that JIS-4is the first3D open-frame-work borophosphate in the family of borophosphates with B/P ratio of2/5.
The structure of JIS-6built up by CoO6octahedra and BO4 and PO4tetrahedra consists of a2-D anionic framework [Co2B4P8O30(OH)4]8-containing8-ring channels in the structure(Figure3).The negative charge of the framework is compensated by the interlayer ammonium cations.The asymmetric unit(Figure S2,Supporting Information)con-tains two crystallographic distinct Co atoms,eight crystal-lographically distinct P atoms,and four crystallographically B atoms.Both of the two Co atoms are in an octahedral environment sharing fiveμ-O atoms with five P atoms and oneμ3-O with two boron atoms.All the crystallographically distinct P atoms are tetrahedrally coordinated to the oxygen atoms.P(1)and P(7)atom atoms are coordinated by three bridging atoms,leaving one terminal P d O group with bond length of1.499(9)A for P(1)d O(2)and1.512(6)A for P-(7)d O(11),respectively.P(2),P(3),P(5),and P(6)share bridging oxygen atoms with adjacent cobalt and boron atoms, leaving one terminal P d O group(P(2)d O(9),P(3)d O(13), P(5)d O(10),and P(6)d O(22)with bond length of1.477(9), 1.517(6),1.512(6),and1.509(6)A,respectively)and one terminal P-OH group(P(2)-O(1)H,P(3)-O(3)H,P(5)-O-(4)H,and P(6)-O(8)H with bond length of1.609(10), 1.598(6),1.577(7),and1.593(6)A,respectively)protruding into the interlayer void space.Both P(4)and P(8)share four bridging oxygen atoms with Co/B atoms.All the tetrahedrally coordinated B atoms coordinate to threeμ-O atoms shared by adjacent P atoms and oneμ3-O shared by two mirror related boron atoms.The B-O bond lengths of1.432(9)-1.496(9)A are in the typical range for borophosphates.
Different from JIS-4and JIS-5with B/P ratio of2/5,JIS-6 possesses1-D open-branched dreier-single ring chain anionic partial structure[BP2O10]7-with B/P ratio of1/2(Figure3c) as FBU.It is noted that JIS-6has a unique anionic partial structure in contrast to the reported ones in the family of1/2. The structure of JIS-6can be viewed as that the1-D FBUs
Figure2.(a)Polyhedron view of the2-D structure of JIS-5;the interlayer Ktions are presented as blue circles.(b)A layer which contains Mn centered borophosphate clusters(polyhedral).The K atoms are omitted for clarity.
1078Inorganic Chemistry,Vol.50,No.3,2011Su et al.
to note that JIS-6contains similar building units,i.e.,transition metal(Co)centered borophosphate heptamer,as those observed in JIS-4and JIS-5.Such metal-centered clusters are common in the borophosphate frameworks,and even the single metal-centered borophosphate cluster com-pound have been reported.37However,JIS-4,-5,and-6 adopt three unique structures because the same borophosphate heptamers are further connected by transition metal ions in different fashions.
Conclusion
We present here the first ionothermal synthesis of three novel open-framework metal borophosphates,JIS-4,JIS-5, and JIS-6.All these structures are based on a similar cluster building unit,i.e.,transition metal-centered borophosphate heptamer.The structure of JIS-4possesses12-ring channels along the[100]direction and8-ring channels along the[010] direction.It is interesting to note that chlorine substituted CoO5Cl octahedral and CoO5square pyramids which are rarely observed in the family of borophosphates appear in the structure of JIS-4.The2-D layer framework of JIS-5contains distorted8-ring windows.It is worth noting that both JIS-4 and JIS-5have the same anionic partial structure of open-branched dreier-single ring heptamer with B/P ratio of2/5and JIS-4is the first3-D open-framework borophosphate in the family of borophosphates with B/P ratio of2/5.The2-D layer structure of JIS-6containing8-ring pore windows possesses a1-D chain anionic partial structure with a B/P ratio of1/2.It is noted that JIS-6has unique anionic partial structure in contrast to the reported ones in the family of borophosphates.The successful preparation of the three new metal borophosphates with unique structures in ionic liquids demonstrates not only that many more open-framework borophosphates with unique structures could be obtained but also that the ionothermal method is a promising method to synthesize new kinds of open-framework materials. Acknowledgment.We thank the National Natural Science Foundation of China and the State Basic Re-search Project of China(Grants:2007CB936402and 2011CB808703)for financial support of this work. Supporting Information Available:Experimental and simulated powder X-ray diffraction(XRD)patterns,in situ temperature dependent powder X-ray diffraction patterns of JIS-4,thermo-gravimetric curves,thermal ellipsoid plots(PDF),and X-ray crystallographic files(CIF)of the three compounds.This material is available free of charge via the Internet at http:// https://www.sodocs.net/doc/e115734833.html,.
Figure3.(a)Polyhedral view of the2-D layered structure of JIS-6.(b)Polyhedral view of the layer containing8-ring pore window and the Co centered borophosphate cluster is highlighted in the circle.(c)The1-D open-branched dreier-single ring chain anionic partial structure with B/P ratio of1/2in the
structure.