Undistorted linear Bi chains with hypervalent bonding in La₃TiBi₅ from single-crystal X-ray diffraction

The crystal structure of the lanthanum titanium bis­muthide La₃TiBi₅ (Pearson code hP18, Wyckoff sequence b d g2) has been established from single-crystal X-ray diffraction data and analyzed in detail using first-principles calculations. There are no anomalies pertaining to the atomic displacement parameter of the Ti site, previously reported based on a powder X-ray diffraction analysis of this compound. The anionic substructure contains columns of face-sharing TiBi₆ octa­hedra and linear Bi chains. Due to a significant La(5d) and Bi(6p) orbital mixing, a perfectly one-dimensional character of the Bi chains is not realised, while a three-dimensional electronic structure is established instead. The latter fact explains the stability of the polyanionic pnictide units against Peierls distortions. The hypervalent bonding in the Bi chains is reflected in a rather long Bi—Bi distance of 3.2264 (4) Å and a typical pattern of bonding and anti­bonding inter­actions, as revealed by electronic structure calculations.

Computing details

Data collection: SMART (Bruker, 2014); cell refinement: SAINT (Bruker, 2014); data reduction: SAINT (Bruker, 2014); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: DIAMOND (Brandenburg, 2014); software used to prepare material for publication: publCIF (Westrip, 2010).

Trilanthanum titanium pentabismuthide

Crystal data

La3TiBi5	Dx = 9.560 Mg m^−3
Mr = 1509.53	Mo Kα radiation, λ = 0.71073 Å
Hexagonal, P63/mcm	Cell parameters from 861 reflections
a = 9.6871 (13) Å	θ = 4.9–26.9°
c = 6.4528 (8) Å	µ = 96.13 mm^−1
V = 524.40 (16) Å^3	T = 200 K
Z = 2	Block, black
F(000) = 1216	0.12 × 0.07 × 0.05 mm

Data collection

CCD area detector diffractometer	217 reflections with I > 2σ(I)
Radiation source: sealed tube	Rint = 0.074
phi and ω scans	θmax = 26.9°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Bruker, 2014)	h = −10→12
Tmin = 0.008, Tmax = 0.046	k = −12→11
4569 measured reflections	l = −8→8
233 independent reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	w = 1/[σ^2(Fo^2) + (0.0129P)^2 + 1.9223P] where P = (Fo^2 + 2Fc^2)/3
R[F^2 > 2σ(F^2)] = 0.019	(Δ/σ)max < 0.001
wR(F^2) = 0.037	Δρmax = 1.27 e Å^−3
S = 1.08	Δρmin = −1.10 e Å^−3
233 reflections	Extinction correction: SHELXL2014 (Sheldrick, 2015b), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
14 parameters	Extinction coefficient: 0.00126 (9)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
La1	0.61818 (9)	0.0000	0.2500	0.0157 (2)
Ti1	0.0000	0.0000	0.0000	0.0169 (10)
Bi1	0.25353 (6)	0.0000	0.2500	0.0152 (2)
Bi2	0.3333	0.6667	0.0000	0.0154 (2)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
La1	0.0152 (4)	0.0163 (5)	0.0161 (4)	0.0082 (3)	0.000	0.000
Ti1	0.0163 (15)	0.0163 (15)	0.018 (2)	0.0082 (7)	0.000	0.000
Bi1	0.0144 (3)	0.0153 (3)	0.0163 (3)	0.00764 (17)	0.000	0.000
Bi2	0.0152 (3)	0.0152 (3)	0.0158 (4)	0.00758 (13)	0.000	0.000

Geometric parameters (Å, º)

La1—Bi1^i	3.2602 (8)	Ti1—Bi1	2.9384 (6)
La1—Bi1^ii	3.2602 (7)	Ti1—Ti1^xiv	3.2264 (4)
La1—Bi2^iii	3.4253 (3)	Ti1—Ti1^xv	3.2264 (4)
La1—Bi2^iv	3.4253 (3)	Bi1—Ti1^xiv	2.9384 (6)
La1—Bi2^v	3.4254 (3)	Bi1—La1^xvi	3.2601 (7)
La1—Bi2^vi	3.4254 (3)	Bi1—La1^xvii	3.2601 (7)
La1—Bi1^vii	3.4575 (6)	Bi1—La1^vii	3.4575 (6)
La1—Bi1^viii	3.4575 (6)	Bi1—La1^viii	3.4575 (6)
La1—Bi1	3.5323 (11)	Bi2—Bi2^xviii	3.2264 (4)
La1—La1^viii	3.9563 (11)	Bi2—Bi2^xix	3.2264 (4)
La1—La1^vii	3.9563 (11)	Bi2—La1^xx	3.4253 (4)
Ti1—Bi1^ix	2.9384 (5)	Bi2—La1^xxi	3.4253 (3)
Ti1—Bi1^x	2.9384 (5)	Bi2—La1^x	3.4253 (5)
Ti1—Bi1^xi	2.9384 (6)	Bi2—La1^vi	3.4253 (3)
Ti1—Bi1^xii	2.9384 (5)	Bi2—La1^xvii	3.4253 (3)
Ti1—Bi1^xiii	2.9384 (5)	Bi2—La1^xii	3.4253 (4)
Bi1^i—La1—Bi1^ii	81.45 (3)	Bi1^x—Ti1—Bi1	92.745 (10)
Bi1^i—La1—Bi2^iii	141.80 (2)	Bi1^xi—Ti1—Bi1	180.0
Bi1^ii—La1—Bi2^iii	73.779 (12)	Bi1^xii—Ti1—Bi1	87.255 (13)
Bi1^i—La1—Bi2^iv	141.80 (2)	Bi1^xiii—Ti1—Bi1	92.745 (13)
Bi1^ii—La1—Bi2^iv	73.779 (12)	Bi1^ix—Ti1—Ti1^xiv	123.299 (7)
Bi2^iii—La1—Bi2^iv	56.193 (8)	Bi1^x—Ti1—Ti1^xiv	56.701 (7)
Bi1^i—La1—Bi2^v	73.780 (10)	Bi1^xi—Ti1—Ti1^xiv	123.299 (8)
Bi1^ii—La1—Bi2^v	141.81 (2)	Bi1^xii—Ti1—Ti1^xiv	123.299 (8)
Bi2^iii—La1—Bi2^v	140.95 (3)	Bi1^xiii—Ti1—Ti1^xiv	56.701 (8)
Bi2^iv—La1—Bi2^v	109.451 (15)	Bi1—Ti1—Ti1^xiv	56.701 (8)
Bi1^i—La1—Bi2^vi	73.780 (10)	Bi1^ix—Ti1—Ti1^xv	56.701 (7)
Bi1^ii—La1—Bi2^vi	141.81 (2)	Bi1^x—Ti1—Ti1^xv	123.299 (7)
Bi2^iii—La1—Bi2^vi	109.451 (15)	Bi1^xi—Ti1—Ti1^xv	56.701 (8)
Bi2^iv—La1—Bi2^vi	140.95 (3)	Bi1^xii—Ti1—Ti1^xv	56.701 (8)
Bi2^v—La1—Bi2^vi	56.193 (8)	Bi1^xiii—Ti1—Ti1^xv	123.299 (8)
Bi1^i—La1—Bi1^vii	74.192 (17)	Bi1—Ti1—Ti1^xv	123.299 (8)
Bi1^ii—La1—Bi1^vii	74.192 (17)	Ti1^xiv—Ti1—Ti1^xv	180.0
Bi2^iii—La1—Bi1^vii	124.029 (4)	Ti1—Bi1—Ti1^xiv	66.597 (16)
Bi2^iv—La1—Bi1^vii	71.376 (8)	Ti1—Bi1—La1^xvi	81.053 (15)
Bi2^v—La1—Bi1^vii	71.377 (6)	Ti1^xiv—Bi1—La1^xvi	81.053 (15)
Bi2^vi—La1—Bi1^vii	124.029 (3)	Ti1—Bi1—La1^xvii	81.053 (14)
Bi1^i—La1—Bi1^viii	74.192 (18)	Ti1^xiv—Bi1—La1^xvii	81.053 (14)
Bi1^ii—La1—Bi1^viii	74.192 (17)	La1^xvi—Bi1—La1^xvii	158.55 (3)
Bi2^iii—La1—Bi1^viii	71.376 (7)	Ti1—Bi1—La1^vii	144.36 (2)
Bi2^iv—La1—Bi1^viii	124.029 (3)	Ti1^xiv—Bi1—La1^vii	77.767 (17)
Bi2^v—La1—Bi1^viii	124.029 (3)	La1^xvi—Bi1—La1^vii	93.835 (4)
Bi2^vi—La1—Bi1^viii	71.377 (6)	La1^xvii—Bi1—La1^vii	93.835 (3)
Bi1^vii—La1—Bi1^viii	137.87 (4)	Ti1—Bi1—La1^viii	77.767 (17)
Bi1^i—La1—Bi1	139.276 (17)	Ti1^xiv—Bi1—La1^viii	144.36 (2)
Bi1^ii—La1—Bi1	139.276 (16)	La1^xvi—Bi1—La1^viii	93.835 (3)
Bi2^iii—La1—Bi1	70.476 (15)	La1^xvii—Bi1—La1^viii	93.835 (3)
Bi2^iv—La1—Bi1	70.476 (15)	La1^vii—Bi1—La1^viii	137.87 (4)
Bi2^v—La1—Bi1	70.475 (14)	Ti1—Bi1—La1	146.701 (8)
Bi2^vi—La1—Bi1	70.475 (14)	Ti1^xiv—Bi1—La1	146.701 (8)
Bi1^vii—La1—Bi1	111.066 (18)	La1^xvi—Bi1—La1	100.724 (17)
Bi1^viii—La1—Bi1	111.066 (18)	La1^xvii—Bi1—La1	100.724 (16)
Bi1^i—La1—La1^viii	116.015 (12)	La1^vii—Bi1—La1	68.934 (18)
Bi1^ii—La1—La1^viii	116.015 (11)	La1^viii—Bi1—La1	68.935 (18)
Bi2^iii—La1—La1^viii	54.726 (8)	Bi2^xviii—Bi2—Bi2^xix	180.0
Bi2^iv—La1—La1^viii	100.99 (2)	Bi2^xviii—Bi2—La1^xx	118.097 (4)
Bi2^v—La1—La1^viii	100.99 (2)	Bi2^xix—Bi2—La1^xx	61.904 (4)
Bi2^vi—La1—La1^viii	54.725 (7)	Bi2^xviii—Bi2—La1^xxi	61.904 (4)
Bi1^vii—La1—La1^viii	165.70 (4)	Bi2^xix—Bi2—La1^xxi	118.097 (4)
Bi1^viii—La1—La1^viii	56.427 (14)	La1^xx—Bi2—La1^xxi	166.36 (3)
Bi1—La1—La1^viii	54.64 (2)	Bi2^xviii—Bi2—La1^x	61.904 (5)
Bi1^i—La1—La1^vii	116.015 (12)	Bi2^xix—Bi2—La1^x	118.097 (5)
Bi1^ii—La1—La1^vii	116.015 (11)	La1^xx—Bi2—La1^x	70.550 (16)
Bi2^iii—La1—La1^vii	100.99 (2)	La1^xxi—Bi2—La1^x	99.631 (8)
Bi2^iv—La1—La1^vii	54.726 (8)	Bi2^xviii—Bi2—La1^vi	118.097 (3)
Bi2^v—La1—La1^vii	54.725 (8)	Bi2^xix—Bi2—La1^vi	61.904 (4)
Bi2^vi—La1—La1^vii	100.99 (2)	La1^xx—Bi2—La1^vi	99.631 (5)
Bi1^vii—La1—La1^vii	56.427 (14)	La1^xxi—Bi2—La1^vi	70.550 (15)
Bi1^viii—La1—La1^vii	165.70 (4)	La1^x—Bi2—La1^vi	91.52 (3)
Bi1—La1—La1^vii	54.64 (2)	Bi2^xviii—Bi2—La1^xvii	61.903 (4)
La1^viii—La1—La1^vii	109.28 (4)	Bi2^xix—Bi2—La1^xvii	118.096 (3)
Bi1^ix—Ti1—Bi1^x	180.000 (13)	La1^xx—Bi2—La1^xvii	91.52 (3)
Bi1^ix—Ti1—Bi1^xi	92.745 (10)	La1^xxi—Bi2—La1^xvii	99.631 (6)
Bi1^x—Ti1—Bi1^xi	87.255 (10)	La1^x—Bi2—La1^xvii	99.631 (6)
Bi1^ix—Ti1—Bi1^xii	92.745 (11)	La1^vi—Bi2—La1^xvii	166.36 (3)
Bi1^x—Ti1—Bi1^xii	87.255 (11)	Bi2^xviii—Bi2—La1^xii	118.096 (4)
Bi1^xi—Ti1—Bi1^xii	92.745 (12)	Bi2^xix—Bi2—La1^xii	61.903 (5)
Bi1^ix—Ti1—Bi1^xiii	87.255 (11)	La1^xx—Bi2—La1^xii	99.631 (9)
Bi1^x—Ti1—Bi1^xiii	92.745 (11)	La1^xxi—Bi2—La1^xii	91.52 (3)
Bi1^xi—Ti1—Bi1^xiii	87.255 (12)	La1^x—Bi2—La1^xii	166.36 (3)
Bi1^xii—Ti1—Bi1^xiii	180.00 (2)	La1^vi—Bi2—La1^xii	99.631 (5)
Bi1^ix—Ti1—Bi1	87.255 (10)	La1^xvii—Bi2—La1^xii	70.550 (15)

Symmetry codes: (i) −y+1, x−y, z; (ii) −x+y+1, −x, z; (iii) x, y−1, z; (iv) x, y−1, −z+1/2; (v) −x+1, −y+1, z+1/2; (vi) −x+1, −y+1, −z; (vii) −x+1, −y, −z+1; (viii) −x+1, −y, −z; (ix) y, −x+y, −z; (x) −y, x−y, z; (xi) −x, −y, −z; (xii) x−y, x, −z; (xiii) −x+y, −x, z; (xiv) −x, −y, z+1/2; (xv) −x, −y, z−1/2; (xvi) −y, x−y−1, z; (xvii) −x+y+1, −x+1, z; (xviii) x, y, −z+1/2; (xix) x, y, −z−1/2; (xx) y, −x+y+1, −z; (xxi) x, y+1, z.