Bis(1-benzyl-3-methylimidazolium-jC 2 )- mercury(II) bis(hexafluoridophosphate) Rosenani A. Haque, a Abbas Washeel Salman, a Madhukar Hemamalini b and Hoong-Kun Fun b *‡ a School of Chemical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and b X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia Correspondence e-mail: hkfun@usm.my Received 5 August 2011; accepted 9 August 2011 Key indicators: single-crystal X-ray study; T = 100 K; mean (C–C) = 0.008 A ˚ ; R factor = 0.032; wR factor = 0.087; data-to-parameter ratio = 12.6. The asymmetric unit of the title complex, [Hg(C 11 H 12 N 2 ) 2 ]- (PF 6 ) 2 , consists of one bis(1-benzyl-3-methylimidazolium)- mercury(II) cation, one half of the cation and an additional Hg II atom, which lies on an inversion centre, and three hexafluoridophosphate anions. The Hg II atoms exist in a linear coordination geometry [C—Hg—C = 178.9 (2) and 180  ] formed by two carbene C atoms from the imidazole rings. In the crystal, the cations and anions are connected via C—HF hydrogen bonds, forming a three-dimensional network. Related literature For details of N-heterocyclic carbenes, see: Herrmann (2002); Arduengo et al. (1991); Herrmann et al. (1998); McGuinness et al. (1999); Wanzlick & Scho ¨nherr (1968). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986). Experimental Crystal data [Hg(C 11 H 12 N 2 ) 2 ](PF 6 ) 2 M r = 834.98 Monoclinic, P2 1 =c a = 15.1260 (17) A ˚ b = 10.3044 (11) A ˚ c = 26.398 (3) A ˚  = 102.275 (2)  V = 4020.5 (8) A ˚ 3 Z =6 Mo K radiation  = 5.97 mm 1 T = 100 K 0.34  0.32  0.05 mm Data collection Bruker APEXII DUO CCD area- detector diffractometer Absorption correction: multi-scan (SADABS; Bruker, 2009) T min = 0.233, T max = 0.751 23876 measured reflections 7062 independent reflections 5985 reflections with I >2(I) R int = 0.046 Refinement R[F 2 >2(F 2 )] = 0.032 wR(F 2 ) = 0.087 S = 1.06 7062 reflections 559 parameters H-atom parameters constrained  max = 1.71 e A ˚ 3  min = 2.05 e A ˚ 3 Table 1 Hydrogen-bond geometry (A ˚ ,  ). D—HA D—H HA DA D—HA C10—H10AF15 i 0.93 2.32 3.240 (7) 171 C11—H11CF6 ii 0.96 2.55 3.375 (7) 144 C13—H13AF7 i 0.93 2.43 3.355 (7) 175 C18—H18AF5 ii 0.97 2.50 3.282 (6) 138 C18—H18BF13 ii 0.97 2.45 3.111 (6) 125 C21—H21AF12 iii 0.93 2.51 3.351 (6) 150 C29—H29BF17 iv 0.97 2.48 3.125 (7) 123 C31—H31AF11 iv 0.93 2.43 3.271 (6) 150 Symmetry codes: (i) x þ 1; y þ 1 2 ; z þ 1 2 ; (ii) x; y þ 1; z; (iii) x; y þ 1 2 ; z þ 1 2 ; (iv) x; y þ 1; z. Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009). RAH and AWS thank Universiti Sains Malaysia (USM) for the FRGS fund (203/PKIMIA/671115), short term grant (304/ PKIMIA/639001) and RU grants (1001/PKIMIA/813023 and 1001/PKIMIA/811157). AWS thanks Universiti Sains Malaysia (USM) for the RU grant (1001/PKIMIA/843090). HKF and MH thank the Malaysian Government and Universiti Sains Malaysia for the Research University Grant No. 1001/PFIZIK/ 811160. MH also thanks Universiti Sains Malaysia for a post- doctoral research fellowship. Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: IS2765). metal-organic compounds m1242 Haque et al. doi:10.1107/S1600536811032235 Acta Cryst. (2011). E67, m1242–m1243 Acta Crystallographica Section E Structure Reports Online ISSN 1600-5368 ‡ Thomson Reuters ResearcherID: A-3561-2009.