www.elsevier.com/locate/inoche

Inorganic Chemistry Communications 10 (2007) 1145–1148

Hydrolysis to the first dumbbell-like high-nuclearity bismuth-oxocluster [Bi12(l3-OH)4(l2-OH)2(l3-O)8(l4-O)2(NO3)6]4+:Synthesis, structure and spectroscopic characterizations

Bing Liu a,*, Wei-Wei Zhou b, Zhi-Qiang Zhou a, Xian-You Zhang c

a College of Science, Northeast Forest University, Harbin, Heilongjiang 150040, PR Chinab State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences,

Fuzhou, Fujian 350002, PR Chinac Material Science and Engineering College, Harbin University of Science and Technology, Harbin, Heilongjiang 150040, PR China

Received 17 May 2007; accepted 25 June 2007Available online 3 July 2007

Abstract

The first dumbbell-like high-nuclearity bismuth-oxo cluster [Bi12(l3-OH)4(l2-OH)2(l3-O)8(l4-O)2(NO3)6](NO3)4 Æ 6H2O was obtainedby diffusing ethanol into the hydrolysate of Bi(NO3)3 aqueous solution. The dumbbell consists of two Bi–O bonds as the handle and two[Bi6(l3-OH)2(l2-OH)(l3-O)4(l4-O)] subunits as the bells. The bell can be regarded as a piercing bracelet-like ring consisted of six edge-sharing tetragons with one cross section enveloped by one l3-O linking three Bi(III) atoms and the other connected by one l2-O as a opencover. The structure is further stabilized by the interactions of Bi� � �Bi, Bi� � �O and hydrogen bondings. The optical gap of 2.85 eV sug-gests that the title compound behaves as semiconductors. The title compound features a blue fluorescence at 441 nm, which is assigned to1P1–1S0 and 3P–1S0 transitions from the s2 electron of Bi3+ cation.� 2007 Elsevier B.V. All rights reserved.

Keywords: Bismuth(III); Crystal structure; Fluorescence; Band gap

The high bismuth density homo and heterometallic bis-muth oxide-based materials [1] can be prepared via chemi-cal vapour deposition (CVD) [2] or via the sol–gel process[3] possessing potential applications in the syntheses ofmaterials such as high-temperature superconductors ornon-volatile random access memories [4]. The synthesesof bulk bismuth-oxo clusters are carried out usually start-ing from hydroxide [5], alkoxides [6], aryl oxides [7], carb-oxylates [8], siloxides [9], phosphonates [10], and ketones[11]. The structural information is very limited because ofthe high Lewis acidity and expandable coordination sphereof Bi(III), and low aqueous solubility of its salts [12]. Theinherent difficulties in hydrolytic pathways are to control

1387-7003/$ - see front matter � 2007 Elsevier B.V. All rights reserved.

doi:10.1016/j.inoche.2007.06.020

* Corresponding author.E-mail address: bliu_1203@yahoo.com.cn (B. Liu).

the compositions, which often results in different speciesto form mixtures [13]. Herein, a dumbbell-like high-nucle-arity bismuth-oxo cluster [Bi12(l3-OH)4(l2-OH)2(l3-O)8-(l4-O)2(NO3)6](NO3)4 Æ 6H2O was isolated via hydrolysisof Bi(NO3)3 aqueous solution, whose crystal structureand spectroscopic properties were presented.

The crystals of the title compound were obtained by dif-fusing ethanol into the hydrolysate of Bi(NO3)3 aqueoussolution [14] . The crystal structure was determined by sin-gle-crystal X-ray crystallography [15]. In the structure,there are two sorts of Bi(III) atoms: four-coordinatedBi1, Bi4 and Bi6 and five-coordinated Bi2, Bi3 and Bi5(Fig. 1). All four-coordinated Bi(III) atoms are coordi-nated by four oxygen atoms as base planes in distortedBiO4 square pyramid geometries with the apical sites occu-pied by the lone-pair electrons from Bi(III) atoms, similarto those in [Bi6(l3-O)4(l3-OH)4]X6 (X = ClO�4 , NO�3 Þ

Fig. 1. The coordination spheres of Bi(III) atoms in the title compound.Selected bond distances (A): Bi1–O6 = 2.126(4); Bi1–O7 = 2.131(4); Bi1–O4 = 2.289(4); Bi1–O3 = 2.461(4); Bi2–O7 = 2.131(4); Bi2–O5 = 2.185(3);Bi2–O2 = 2.330(4); Bi2–O3 = 2.480(4); ;Bi2–O41 = 2.749(4); Bi3–O8 =2.181(4); Bi3–O4 = 2.182(4); Bi3–O7 = 2.214(4); Bi3–O4A = 2.540(4);Bi3–O33 = 2.731(5); Bi4–O5 = 2.144(4); Bi4–O6 = 2.171(4); Bi4–O3 =2.373(3); Bi4–O1 = 2.403(4); Bi5–O5 = 2.145(4); Bi5–O8 = 2.163(5); Bi5–O2 = 2.241(3); Bi5–O1 = 2.524(4); Bi5–O22 = 2.756(6); Bi6–O6 =2.151(4); Bi6–O8 = 2.152(4); Bi6–O1 = 2.271(5); Bi6–O4 = 2.406(4);Bi1� � �Bi3 = 3.5140(6); Bi1� � �Bi6 = 3.5761(6); Bi1� � �Bi4 = 3.6979(8);Bi2� � �Bi5 = 3.6013(6); Bi3� � �Bi6 = 3.5737(6); Bi4� � �Bi6 = 3.6630(6);Bi5� � �Bi6 = ; 3.6641(7); symmetry code: A = �x, �y + 4, �z + 1.

1146 B. Liu et al. / Inorganic Chemistry Communications 10 (2007) 1145–1148

[5b,5c] and [Bi9(l3-O)8(l3-OR)6]5+ [6]. The five-coordi-nated Bi(III) atoms located in square pyramids withs = 0.0632 for Bi2, 0.2367 for Bi3 and 0.1206 for Bi5 (sdefined as (b � a)/60 [16], a and b being the bigger bondangles around bismuth; s = 0 for an ideal square pyramidwith a = b = 180�). The bond-valence sums (BVS) ofBi1–Bi6 close to 3 given by the valence-sum calculationsare 2.75, 2.72, 2.75, 2.56, 2.83, and 2.73, respectively, show-ing all Bi atoms are Bi(III) cations. Similar calculationsgive BVS of 1.35, 1.189 and 1.180 for O1–O3, indicatingO1, O2 and O3 should be OH� anions. While BVS forO4–O8 being 2.086, 2.500, 2.559, 2.508 and 2.446, respec-tively, it shows that they should be O2� anions. In theasymmetry unit, 18 positive charges on six bismuth(III)cations are balanced by three OH�, five NO�3 and ten neg-ative charges on five O2� anions, indicating the charge bal-ance consideration agrees with the valence-sumcalculations.

The structure motif of the title compound can be bestdescribed as a dumbbell-like bismuth-oxo cluster withBi3–O4A and Bi3A–O4 bonds (A = �x, 4 � y, 1 � z) asthe handle and two symmetry-related [Bi6(l3-OH)2

(l2-OH)(l3-O)4(l4-O)] subunits as the bells (Fig. 2). It isnoteworthy that, though the Bin cluster is common, thedumbbell-like bismuth-oxo cluster is first found. All

OH� and O2� anions except O2 and O6 adopt l3-modesto alternately connect Bi(III) atoms to form a piercingbracelet-like ring consisted of six edge-sharing tetragons(Fig. 3). One of its cross section is further enveloped byl3-O6 linking Bi1, Bi4 and Bi6. However the other oneis not close with l2-O2 linking Bi2 and Bi5 like an opencover. The l-OH ligands in the title compound are sharedasymmetrically among the Bi atoms, with the average dis-tance of Bi–OHl2 (2.285 A) 0.16 A shorter than the one ofBi–OHl3 (2.452 A). The average distance of Bi–OOH

bonds is 2.405 A vs. 2.191 A for those of Bi–O2� ones.Bi–O2�

l3 distances for O5–O8 locate in a narrow range2.126–2.214 A, indicating l3-O2� anions nearly equablyconnect with Bi atoms. However, the l4-O(4)2� ligand islinked asymmetrically among four Bi atoms, with Bi3–O4A bond at least 0.25 A longer than the other closethree, suggesting three predominantly dative interactionsto Bi atoms. Despite the existence of metal� � �metal inter-actions in polyoxo clusters of the heavy main-group ele-ments are still disputed [17], the Bi� � �Bi distancesranging from 3.514 to 3.833 A are significantly shorterthan twice the van der Waals radius of Bi (2.4 A) butlonger than typically identified as ‘‘bonding’’ in Bi clusters(dBi–Bi = 3.0–3.1 A) [18], supporting the existence of Bi–Biinteractions.

In the structure, there are strong hydrogen bondingsbetween lattice water: O1W� � �O2W = 2.734(7) and2.826(6); O1W� � �O3W = 2.949(7) A. Strong inter- andintra-molecular hydrogen bondings exist between NO�3and the lattice water that may further stabilize the lattice,such as O2W� � �O2 = 2.768(6), O2W� � �O23 = 2.864(6),O3W� � �O32 = 2.960(6), O3W� � �O42 = 3.018(7), O3W� � �O43 = 3.014, O3W� � �O31 = 3.045 A. Additional weakinteractions around Bi atoms with NO�3 with Bi� � �Onitrate

range from 2.778(4) to 3.091(5) A, which partly satisfythe coordination requirements of Bi(III) atoms.

The polybismuth-oxo clusters raise much interest fromthe potential semiconducting character. The optical prop-erty of the title compound was assessed by its optical dif-fuse reflectance data [19]. The Kubelka-Munk (orremission, F) function converted from the diffuse reflec-tance data was plotted according to the diffuse reflectancedata (Fig. S1). Optical absorption spectrum indicates theoptical gap Eg = 2.85 eV, suggesting that the compoundbehaves as semiconductors.

In contrast to the studies of pharmaceuticals andhybrid inorganic–organic materials, the fluorescent stud-ies are very limited. The fluorescent property of the titlecompound was explored in the solid state at room tem-perature. It can be observed that an intense blue fluores-cence with a broad emission peak at ca. 441 nm wasproduced on excitation at 370 nm (Fig. S2). The blueemission peak was assigned to 1P1–1S0 and 3P–1S0 transi-tions from the s2 electron of Bi3+ cations [20]. With blueray as one of the three basic colors, the title compoundmay have potential application in developing new theblue emission materials.

Fig. 2. The dumbbell-like high-nuclearity bismuth-oxo cluster. For clarity, NO�3 anions are omitted.

Fig. 3. The linkage of the subunit [Bi6(l3-OH)2(l2-OH)(l3-O)4(l4-O)].

B. Liu et al. / Inorganic Chemistry Communications 10 (2007) 1145–1148 1147

Acknowledgement

This work has been supported by Heilongjiang provincedepartment of education (11523014).

Appendix A. Supplementary material

Supplementary data associated with this article can befound, in the online version, at doi:10.1016/j.inoche.2007.06.020.

References

[1] (a) K.H. Whitmire, Chemtracts, Inorg. Chem. 7 (1995) 167;(b) J.H. Thurston, D. Trahan, T. Ould-Ely, K.H. Whitmire, Inorg.Chem. 43 (2004) 3299;(c) J.H. Thurston, A. Kumar, C. Hofmann, K.H. Whitmire, Inorg.Chem. 43 (2004) 8427;(d) S. Parola, R. Papiernik, L.G. Hubert-Pfalzgraf, C. Bois, J. Chem.Soc. Dalton (1998) 737;(e) M. Hunger, C. Limberg, P. Kircher, Angew. Chem. 111 (1999)1171;(f) V.G. Kessler, N.Y. Tiurova, E.P. Turevskaya, Inorg. Chem.Commun. 5 (2002) 549.

[2] (a) P.A. Williams, A.C. Jones, M.J. Crosbie, P.J. Wright, J.F. Bickley,A. Steiner, H.O. Davies, T.J. Leedham, G.W. Critchlow, Chem. Vap.Depos. 7 (2001) 205;(b) R. Potter, P.A. Marshall, J.L. Roberts, A.C. Jones, P.R.Chalker, M. Vehkamaeki, M. Ritala, M. Leskela, P.A. Williams,

H.O. Davies, N.L. Tobin, L.M. Smith, Mater. Res. Soc. Symp.Proc. 784 (2004) 97.

[3] (a) F. Soares-Carvalho, P. Thomas, J.P. Mercurio, B. Frit, S. Parola,J. Sol–Gel Sci. Technol. 8 (1997) 759;(b) K.A. Vorotilov, M.I. Yanovskaya, E.P. Turevskaya, A.S. Sigov, J.Sol–Gel Sci. Technol. 16 (1999) 109;(c) E.P. Turevskaya, V.B. Bergo, K.A. Vorotilov, A.S. Sigov, D.Benlian, J. Sol–Gel Sci. Technol. 13 (1998) 889;(d) S. Parola, R. Papiernik, L.G. Hubert-Pfalzgraf, S. Jagner, M.Hakansson, J. Chem. Soc. Dalton (1997) 4631;(e) Y.T. Kim, C. Hwang, H.K. Chae, Y.K. Lee, W.I. Lee, Y.W.Dong, H. Yun, J. Sol–Gel Sci. Technol. 19 (2000) 301;(f) W.F. Su, Y.T. Lu, Mater. Chem. Phys. 80 (2003) 632;(g) K. Kato, C. Zheng, J.M. Finder, S.K. Dey, Y. Torii, J. Am.Ceram. Soc. 81 (1998) 1869;(h) J.H. Thurston, K.H. Whitmire, Inorg. Chem. 42 (2003) 2014.

[4] M. Mehring, Coord. Chem. Rev. 251 (2007) 974.[5] (a) J.H. Thurston, D.C. Swenson, L. Messerle, Chem. Commun.

(2005) 4228;(b) G. Gattow, D. Schott, Z. Anorg. Allg. Chem. 324 (1963)31;(c) N. Henry, M. Evain, P. Deniard, S. Jobic, O. Mentre, F.Abraham, J. Solid State Chem. 176 (2003) 127.

[6] K.H. Whitmire, S. Hoppe, O. Sydora, J.L. Jolas, C.M. Jones, Inorg.Chem. 39 (2000) 85.

[7] (a) L. Liu, L.N. Zakharov, A.L. Rheingold, T.A. Hanna, Chem.Commun. (2004) 1472;(b) C.M. Jones, M.D. Burkart, K.H.J. Whitmire, Chem. Soc., Chem.Commun. (1992) 1638.

[8] (a) V.V. Sharutin, I.V. Egorova, O.K. Sharutina, T.K. Ivanenko,N.Yu. Adonin, V.F. Starichenko, M.A. Pushilin, A.V. Gerasimenko,Russ. J. Coord. Chem. 31 (2005) 2;

1148 B. Liu et al. / Inorganic Chemistry Communications 10 (2007) 1145–1148

(b) P.C. Andrews, G.B. Deacon, C.M. Forsyth, P.C. Junk, I. Kumar,M. Maguire, Angew. Chem. Int. Ed. 45 (2006) 5638.

[9] (a) D. Mansfeld, M. Mehring, M. SchMrmann, Angew. Chem. Int.Ed. 117 (2005) 250;(b) D. Mansfeld, M. Mehring, M. SchMrmann, Angew. Chem. Int.Ed. 44 (2005) 245;(c) M. Mehring, D. Mansfeld, S. Paalasmaa, M. SchMrmann, Chem.Eur. J. 12 (2006) 1767;(d) M. Mehring, S. Paalasmaa, M. Schurmann, Eur. J. Inorg. Chem.(2005) 4891.

[10] M. Mehring, M. SchMrmann, Chem. Commun. (2001) 2354.[11] E.V. Dikarev, H. Zhang, B. Li, Angew. Chem. Int. Ed. 45 (2006)

5448.[12] (a) G.G. Briand, N. Burford, T.S. Cameron, Chem. Commun. (2000)

13;(b) P.J. Sadler, H. Li, H. Sun, Coord. Chem. Rev. 185–186 (1999) 689.

[13] (a) N.Ya. Turova, Russ. Chem. Rev. 73 (2004) 1041;(b) C.D. Chandler, C. Roger, M.J. Hampden-Smith, Chem. Rev. 93(1993) 1205.

[14] The reagents and solvents were used directly as supplied commerciallywithout further purification. 0.1 mmol, 48.7 mg Bi(NO3)3 Æ 5H2O wasdissolved in 25 ml water and stirred at 90 �C for 1 h, then filtered. Thefiltrate was covered with ethanol in a tube. Over a period ofapproximated 10 days, block colorless crystals of 12.9 mg wereobtained around the interface. Elemental analysis (%), Found (calcd):H, 0.60 (0.52); N, 4.05 (4.00). IR data (in KBr, cm�1): 3158(br, s),2410(w), 2346(w), 1762(w), 1685(w), 1623(w), 1382(vs), 1317(vs),1041(w), 811(w), 7253(w), 698(w), 568(s), 418(w).

[15] Date collection for the compound was performed on Rigaku MercuryCCD diffractometer equipped with graphite-monochromated Mo Karadiation (k = 0.71073 A). Intensity data was collected by the narrowframe method at 293 K and corrected for Lorentz and polarizationeffects as well as for absorption by the x scan technique and werereduced using CrystalClear program. The structure was solved by

direct methods using SHELXTLTM package of crystallographicsoftware and refined by full-matrix least-squares technique on F2.All non-hydrogen atoms were refined with anisotropic thermalparameters. Crystallographic data for the structure reported herehave been deposited with FIZ Karlsruhe (Deposition CSD Number:418079). Crystal data: H18Bi12N10O52, crystal dimensions:0.245 · 0.117 · 0.080 mm3, FW = 3498.00, monoclinic, space groupP21/n, a = 15.348(3) A, b = 9.1739(17) A, c = 17.142(3) A, b =114.050(2)�, V = 2204.2(7) A3, Z = 2, Dc = 5.271 mg/m3, l =47.864�, F(000) = 3000, GOF = 1.004, D/rmax/min = 0.435/0.016,qmax/min = 2.608/ � 1.943. Data collection (2.31 < h < 26.06�) gavethe final R1 = 0.0394, wR2 = 0.0806 and all data R1 = 0.0609,wR2 = 0.0895 for 3281 observed reflections with I > 2r(I) out of4339 unique reflections (Rint = 0.0947).

[16] A.W. Addison, T.N. Rao, J. Reedjik, J. van Riju, G.C. Verschoor, J.Chem. Soc. Dalton (1984) 1349.

[17] (a) C. Janiak, R. Hoffmann, J. Am. Chem. Soc. 112 (1990) 5924;(b) H. Kunkely, A. Vogler, Chem. Phys. Lett. 187 (1991) 609;(c) L.A. Bengtsson, R. Hoffmann, J. Am. Chem. Soc. 115 (1993) 2666;(d) F.P. Arnold, J.K. Burdett, L.R. Sita, J. Am. Chem. Soc. 120(1998) 1637.

[18] V.V. Sharutin, I.V. Egorova, O.K. Sharutina, T.K. Ivanenko, N.Y.Adonin, V.F. Starichenko, M.A. Pushilin, A.V. Gerasimenko, Russ.J. Coord. Chem. 29 (2003) 902.

[19] (a) W.W. Wendlandt, H.G. Hecht, Reflectance Spectroscopy, Inter-science Publishers, New York, 1966;(b) G. Kotuem, Reflectance Spectroscopy, Springer-Verlag, NewYork, 1969.

[20] (a) X.H. Yu, H.H. Zhang, Y.N. Cao, Y.P. Chen, Z. Wang, J. SolidState Chem. 179 (2006) 247;(b) P.F. Smet, J. Van Gheluwe, D. Poelman, R.L. Van Meirhaeghe, J.Lumin. 104 (2003) 145;(c) H.F. Folkerts, J. Zuidema, G. Blasse, Chem. Phys. Lett. 249(1996) 59.