CIT-13: DO Family

Periodic Building Unit (PerBU):

Layer symmetry

2D cell parameters

a = 10.50 Å

b = 13.50 Å

gamma = 90°

To facilitate understanding of the connectivity patterns shown below, O atoms that connect to a single row of d4r units have been highlighted in the CFI layer shown to the right.

Intergrowth Family CIT-13

Periodic Building Unit

Connecting unit

	Connecting unit	d4r

References


		Kang, J.H., Xie, D., Zones, S.I., Smeets, S., McCusker, L.B. and Davis, M.E.
			"Synthesis and characterization of CIT-13, a germanosilicate molecular sieve with extra-large pore openings"
			Chem. Mater., 28, 6250-6259 (2016)

Connectivity pattern

Examples

Positions of d4r unit connectors in a row
There are two possible positions for a row of d4r units above the CFI layer. The position of the first d4r unit (along a) determines the positions of all the other d4r units in that row.

Symmetry Operations	Translation	Comment	Image
	0	d4r units in position 1
	1/2a	d4r units in position 2

Disorder along b: arrangements of the rows of d4r unit connectors
The arrangement of the rows of d4r units is not necessarily periodic along b. Each row can be the same as the neighboring one or shifted by 1/2a.


Second row identical to first with no shift along a	Second row shifted by 1/2a with respect to first

Examples

Disorder along c: stacking of the layers of connectors
Each CFI layer (green) is generated from the previous one (gray) by a mirror plane. The CFI layers themselves are ordered along c. However, the d4r units in the connecting layers can also be disordered along c, making the disorder 2-dimensional (along both b and c). The rows of d4r unit connectors can be stacked along the [001] direction using either of the following connectivity patterns

Symmetry Operations	Translation^*	Comment	Image
	0a + 1/2b
	1/2a +1/2b

^* relative to the previous layer of connectors

Effect on channel system
The disorder does not block the channel system. However, the 10-ring channel becomes sinusoidal when both d4r positions are present in a single layer of d4r units (i.e. it is no longer straight as in polymorph A or B below).

Simplest ordered end-members

The color of the connectors between the layers reflects those shown in the tables above.


Polymorph CIT-13_A

Cell Parameters:	orthorhombic	C m m m (# 65)
	a = 27.2188 Å	b = 13.9547 Å	c = 10.5278 Å
	α = 90.0000°	β = 90.0000°	γ = 90.0000°
	Volume =	3998.8 Å³
Framework Density (FD_Si):	16.0

	Ring sizes (# T-atoms):	14 10 6 5 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 2-dimensional

Maximum diameter of a sphere:
	that can be included	8.29 Å
	that can diffuse along	a: 2.38 Å	b: 4.28 Å	c: 7.5 Å
		[0 0 1] : 7.5 Å
		addional volume data

Composite Building Units:


d4r	mtt	cas	non	ton

In this space group and setting, the ordered connecting rows are along [001] and the layers are stacked along [100]

	Note: This polymorph has NOT been observed as a pure ordered material


Polymorph CIT-13_B

Cell Parameters:	orthohombic	I m m m (# 71)
	a = 27.0454 Å	b = 13.6820 Å	c = 10.2908 Å
	α = 90.0000°	β = 90.0000°	γ = 90.0000°
	Volume =	3808.0 Å³
Framework Density (FD_Si):	16.8

	Ring sizes (# T-atoms):	14 10 6 5 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 2-dimensional

Maximum diameter of a sphere:
	that can be included	8.28 Å
	that can diffuse along	a: 2.04 Å	b: 3.83 Å	c: 7.24 Å
		[0 0 1] : 7.24 Å
		addional volume data

Composite Building Units:


d4r	mtt	cas	non	ton

In this space group and setting, the ordered connecting rows are along [001] and the layers are stacked along [100]

	Note: This polymorph has NOT been observed as a pure ordered material


Polymorph CIT-13_C

Cell Parameters:	orthorhombic	C m c m (# 63)
	a = 10.4578 Å	b = 27.7606 Å	c = 27.2022 Å
	α = 90.0000°	β = 90.0000°	γ = 90.0000°
	Volume =	7897.3 Å³
Framework Density (FD_Si):	16.2

	Ring sizes (# T-atoms):	14 10 6 5 4
	Channel dimensionality:	Topological (pore opening > 6-ring): 2-dimensional

Maximum diameter of a sphere:
	that can be included	8.14 Å
	that can diffuse along	a: 7.45 Å	b: 3.92 Å	c: 2.22 Å
		[1 0 0] : 7.45 Å
		addional volume data

Composite Building Units:


d4r	mtt	cas	non	ton

In this space group and setting, the ordered connecting rows are along [100] and the layers are stacked along [001]

	Note: This polymorph has NOT been observed as a pure ordered material